You absolutely must meet my forever bff: this one pot incredible caramelized onion spinach chicken pasta bake. Also known as heaven on earth.
Some of my best recipes come to me when I’m peeking around in my fridge, trying to figure out what to make to use up ingredients without going to the store. This healthy chicken pasta bake is no different and is made with simple ingredients that you might already have on-hand.
It’s creamy, slightly sweet thanks to those juicy caramelized onions, packed with protein, and has some pretty awesome lick-your-plate-clean kinda magic flavors happening. I swear I could bathe in the parmesan cheese sauce that soaks up the brown bits at the bottom of the pan from the caramelized onions and chicken.
Ingredients in this healthy chicken pasta bake
I was feeling seriously inspired by the parmesan sauce in my healthier tuna noodle casserole, and when I found two bags of spinach that needed to be used up, an onion lurking in the pantry and some parmesan, I knew magic was about to be made. Here are the ingredients you need:
- Pasta: I love shells in this recipe but you can use any pasta you’d like — including gluten-free! I think penne pasta or fusilli would be so fun.
- Chicken: I like to use boneless skinless chicken breast, but chicken thighs will also work.
- Seasonings: the only seasonings you’ll need to give this recipe the perfect flavor are garlic powder, salt & pepper. You could also add a kick of heat with red pepper flakes!
- Veggies: we’re using TWO full bags of spinach, which will seem like it’s a lot, but it cooks down a ton and is perfect mixed in with the pasta and sauce. You’ll also be caramelizing some onions!
- For the sauce: that creamy parmesan sauce is made with butter, all-purpose flour (or whole wheat or gluten-free), milk, and parmesan cheese. That’s right, there’s no heavy cream involved, but it tastes like a better alfredo sauce!
- Bread crumbs: I like to use panko bread crumbs for the toasty topping. Feel free to use gluten-free bread crumbs!
Customize this spinach chicken pasta bake
Feel free to make this recipe your own! Here’s what I can recommend for substitutions and/or additions:
- Choose your veggies: I think this recipe would be delicious with mushrooms, peas, broccoli, and even sun dried or regular tomatoes.
- Make it vegetarian: feel free to throw in a can of rinsed, drained chickpeas or white beans instead of the chicken.
- Go gluten-free: simply use your fav gluten-free noodles, gluten-free all purpose flour in the sauce, and gluten-free bread crumbs on top. You could also substitute crushed up tortilla chips, potato chips, or gluten-free crackers for the topping!
- Try it dairy free: I suggest using vegan butter, a dairy free milk of choice (such as unsweetened almond milk) and dairy free parmesan cheese.
Looking for a quick protein option?
You could easily throw in some shredded rotisserie chicken instead of cooking the chicken for this pasta casserole! It’s a great way to use up leftover chicken, too.
Stovetop option
If you prefer, you can skip the bread crumbs and the baking of the pasta. We do this often when we want to eat quickly and it’s still just as delicious! Feel free to crumble crackers on top if you’d still like a little buttery crunch.
How to caramelize onions
I know caramelizing onions can feel intimidating, but it’s easier to do than you think!
- Add olive oil or butter, sliced onions, and salt and pepper to a large pot and place over medium heat; stir to coat.
- Cook onions, stirring occasionally; check your onions every 5-10 minutes until they have completely caramelized and turned golden brown.
- If the onions appear to be getting too dark or sticking too much to the bottom of the pan, then simply reduce the heat a bit and/or add a teaspoon or two of water at a time. Easy!
Make it ahead of time
- Prep it ahead of time: feel free to make this chicken pasta bake ahead of time and bake it a day or two later! Simply make the recipe as directed, but do not add the bread crumbs. Instead, cover with foil and place in fridge until ready to bake. Once ready to bake, add the bread crumbs as directed and bake. You make need to add 5-10 minutes of extra baking time.
- Freezer-friendly option: if you want to freeze this chicken pasta bake ahead of time, make the recipe as directed, but skip the bread crumb topping. Place the assembled pasta bake in a freezer-safe pan, cover, and place it in the freezer until you’re ready to bake. Once ready to bake, thaw the pasta bake in the refrigerator overnight. Once thawed, add the bread crumb topping and bake as directed!
Storing tips
Store any leftover chicken pasta bake in airtight containers in the refrigerator for up to 3-4 days. Simply reheat leftovers in the microwave until warm. Otherwise, follow the freezing instructions above!
Tools you’ll need
Get all of my favorite kitchen tools here!
More pasta recipes to try
- Buffalo Cauliflower Mac and Cheese
- Spinach Garlic Parmesan Orzo with Crispy Bacon
- Brown Butter Pistachio Pesto Pasta with Chickpeas
- One Pot Cheesy Mushroom Spinach Beef Pasta
- Spicy Brown Butter Goat Cheese Pasta with Sweet Corn & Honey Roasted Butternut Squash
Get all of my delicious pasta recipes here!
I know you’re going to LOVE this spinach chicken pasta bake! Be sure to leave a comment and rate the recipe below if you make it. Thanks for being here — I appreciate you! xo.
Easy Caramelized Onion Spinach Chicken Pasta Bake
Ingredients
- For the pasta:
- 10 ounces dry pasta shells (or use rotini, fusilli, or whatever pasta you’d like -- even gluten-free!)
- For the chicken:
- 1 tablespoon olive oil
- 1 pound boneless skinless chicken breast, diced into ½ inch cubes
- 1/2 teaspoon garlic powder
- Freshly ground salt and pepper
- For the caramelized onions & spinach:
- ½ tablespoon olive oil (or butter)
- 2 large yellow onions, sliced
- Freshly ground salt and pepper
- 10-12 ounces fresh spinach (from 2 (5-ounce bags of spinach)
- For the parmesan cheese sauce:
- 3 tablespoons salted butter
- ¼ cup all purpose flour (or whole wheat flour or all purpose gluten-free flour)
- 2 cups 2% or whole milk (or sub unsweetened almond milk)
- ½ cup grated parmesan cheese
- 1 teaspoon kosher salt
- ½ teaspoon garlic powder
- Freshly ground black pepper
- For the topping:
- ½ cup panko bread crumbs, gluten-free if desired
- 1 tablespoon salted butter
Instructions
- Prep your pan: Preheat your oven to 350 degrees Spray a 2-quart baking dish or 11x7 inch baking pan with nonstick cooking spray, or grease with olive oil or butter.
- Cook the pasta: Boil the noodles until al dente, according to the directions on the package. Once done cooking, drain and set aside.
- Cook the chicken: add ½ tablespoon olive oil to a large pot and place over medium-high heat. Add in diced chicken, season with garlic powder and salt and pepper; cook for 5-7 minutes or until chicken is no longer pink. Transfer chicken to a large bowl once done cooking.
- Caramelize the onions and spinach: In the same pot you cooked chicken, add in ½ tablespoon olive oil or butter, onions, and salt and pepper; stir to coat. Cook onions, stirring occasionally; check your onions every 5 minutes until they have completely caramelized and turned golden brown. If the onions appear to be getting too dark or sticking too much to the bottom of the pan, then simply reduce the heat a bit. You can also add in a few teaspoons of water or a splash of white wine to help deglaze the pan. Once the onions have caramelized, reduce heat to low and stir in spinach with the onions; cooking until spinach wilts, 2 minutes. Remove from heat and transfer to the bowl with the chicken.
- Make the sauce: In the same pot, add in 3 tablespoons of butter and place over medium heat. Once butter is melted, whisk in a little bit of the flour and then slowly add in milk, a little bit at a time, alternating with the flour and vigorously whisking away any lumps. Bring mixture to a boil, then reduce heat to a simmer and stir every so often, until the sauce thickens up.
- Once sauce has thickened up a bit, turn off the heat and stir in parmesan cheese, garlic powder, salt, and LOTS of freshly ground black pepper.
- Assemble the pasta bake: Next stir in cooked noodles, spinach and caramelized onions and chicken. Season again with salt and pepper, to taste. Pour mixture into your prepared baking pan and spread out towards the edges.
- Bake: In a small bowl, mix bread crumbs with melted butter. Sprinkle bread crumb mixture on top of casserole and bake for 25 minutes or until bread crumbs are golden brown. Serves 6.
Recipe Notes
Nutrition
Recipe by: Monique Volz // Ambitious Kitchen | Photography by: Eat Love Eats
This post was originally published on March 19th, 2020, republished on February 26th, 2023, and republished on September 28th, 2025.
I’ve made this one a few times written exactly as is and it’s delish, one of my husbands fav’s!
I had to improvise a bit last night and cut the recipe down, (made 4 instead of 6 servings) and subbed in smoked spinach feta chicken sausage (sliced and browned) and used a protein penne and added some chopped up artichokes. It was awesome, thanks for the constant inspiration and quality recipes Monique!
Amazing! This one’s great for customizing, and chicken sausage sounds SO good.
Wow! This was a hit with my whole family. My toddler ate their whole serving. Will definitely make it again. Left off the breading topping since I didn’t have any.
So happy to hear that!
This was delicious Monique. I can’t eat dairy so I used non dairy milk, butter, and cheese. It turned out perfectly!
Perfect! So glad you loved it!
I just didn’t think this was THAT flavorful 🫣 It was nice and comforting and the recipe is well written. I saw another commenter say they added sun dried tomatoes and I think that’s a great idea. This feels like a good base recipe that you could add other flavors to. I was a little surprised the recipe doesn’t call for any fresh garlic and just uses garlic powder and parmesan really. I also am glad the recipe only called for 10oz of pasta and honestly think you could go down to just 8oz to avoid overfilling your casserole dish and have an even better ratio with the chicken, onions, and spinach
Be sure to add salt to taste in the sauce – that will really help bring out the flavor! I wanted to keep this nice and simple, but you can absolutely add your favorite mix-ins.
Omg I have been sleeping on this recipe for FAR too long. I opted to not bake it and just top it with butter-toasted panko breadcrumbs. I ate my leftovers so slowly tonight for dinner because I didn’t want it to end. 😆
So glad you loved this one!!
This is so good!! Will definitely be making again.
This carmelized onion spinach chicken pasta bake was a big hit with my family last night. It has lots of flavor and packed with good nutrients. I will be making this again!
I’m so glad! One of my family’s favorite dinners, too 🙂
This dish is SO delicious. It’s a little labor intensive so I like to make it on a Sunday-but it’s worth the time. I’ve made it as the recipe states but also subbed in finely chopped kale for the spinach and 1% milk for the almond milk and all versions have turned out great.
One of our fav cozy dinners! Glad you love it!
I love your recipes, especially because we are a gluten free home. I made this with Bob’s Red Mill GF all purpose flour and it was the consistency of velveeta! If we threw the roux against the wall, it would stay there forever. Because I used the status quo GF flour and it happened almost immediately, I thought it might deserve a note within the recipe itself. It is easy to test via steps 5 and 6. Maybe I needed a higher quality grated cheese? Or had to bake it versus the alternate stovetop method?
Hi! This could be for a few different reasons, but I don’t think the GF flour was the culprit. It sounds like the cheese sauce was overcooked (which causes the cheese proteins to clump together), which can happen if it’s added to the sauce when it’s too hot / the heat is too high on the stove. What type of cheese did you use? The kind from the bag also has additives that can give the sauce a strange texture. Be sure to not overmix the sauce, too, because it can emulsify and create a gummy texture. I hope those help!
If I wanted to use a 12.75×10.4 inch pan, would I be able to multiply the recipe by 1.5 without the pan overflowing?
Hi! I think that should work well.
Just made this tonight and it was a big hit!!! Everyone loved it and my nephew went back for a 2nd big helping and he’s a picky eater. Based on a previous reviews, I doubled the recipe and added mushrooms, sun dried tomatoes, some artichokes-and baked in a lasagna pan. Truly delicious and will be saved under my ‘favorites’ to make many times in the future!! Thank you Monique!!
Amazing! Love those mix-ins 🙂
Was excited to try this after reading all the amazing reviews. It was just OK. My family didn’t love it and frankly it was quite a lot of effort! It did make ALOT so if my family had loved it then it would be worth the time.
There wasn’t enough sauce. If I ever make it again I would 💯 double the sauce. Also I would do less onions- I love caramelized onion but it was quite strong.
I followed the recipe EXCEPT I cooked my chicken breast in the instant pot while I was cooking the pasta on the stove (which is how I cook my chicken for most recipes because I don’t like to handle raw meat and it chops or shreds easily this way).
Sorry to hear that it wasn’t a big hit! I’ve always found that this had enough sauce to coat the chicken and pasta. Did you by chance use more chicken than the recipe called for? That’s all I can think may have happened, or that the sauce may have thickened up to much before adding it to the pasta bake. Either way absolutely feel free to double the sauce and reduce the onions next time – this one’s flexible! Be sure to salt to taste when you’re making the sauce, too, because salt = flavor when it comes to a cheese sauce.
Wondering if anyone has used a combination of whole milk and chicken broth to make this? I’d love to try one cup of milk and 3/4 a cup homemade chicken broth but I don’t want to mess it up!!
In the sauce? I think that should work!
How would you go about making this with cream instead of the milk based sauce? What ingredients would you omit (flour, etc.)?
Can this be made ahead and cooked another day?
Yes! Check out the full post for make-ahead instructions.
This has become a regular recipe in our house. I make it without chicken and sub chickpea pasta to still get the protein and it works great! I also like to add some gruyere cheese.
Perfect! I am so glad everyone is loving this recipe and it is a hit, Jenna. Thanks so much for your comment ❤️
My husband went insane over this. Probably helped that I forgot to get spinach so that got left out. I had some heavy cream to use up, so incorporated a bit with the 1% milk I had. It did seem dry before baking and I ended up making a second round of the sauce, and used probably 2/3 of that. Especially knowing I’d have leftovers and the pasta would probably soak up some of the moisture, it was a good call.
Ahh this is so great! Happy to hear that you are loving this recipe and it turned out great for you!
This was great! I accidentally used vanilla almond milk, but didn’t say anything to my husband to see if he’d notice. Nope! He had no idea. Thanks for the recipe, will be making this again!
AH this is so funny! Glad this recipe was a hit, even with the vanilla almond milk lol
I truly rarely ever leave comments, but this dish is amazing. I cook 5-6 nights a week, and try many, many new recipes on a regular basis. My husband said this is one of the best things I have ever made – it is in a weekly rotation now (a rarity in our house) and we have made it for every guest/dinner party we have had since discovering it. The last few times I added artichoke hearts and sun dried tomatoes and its amazing. A great recipe as is, but also a great base to try new additions.
Aw thank you so much, Katheryn. So glad this recipe is a hit for you and your husband and you both are enjoying it. Thank you for your review, I really appreciate it!
Hello! So excited to try your recipes! Do you think I can sub chicken or beef broth/stock for the milk? Would that not work? TIA!
It won’t turn out as creamy. Let me know if you give this recipe a try!
This recipe was fantastic. I used Banza chickpea pasta and gluten free breadcrumbs. The flavor was great. I was in a hurry and needed to make 2 of them so I cheated and used canned chicken. It still tasted great. This a great dish to make ahead and take to someone–just add the breadcrumbs right before you bake it. Thanks for all the great recipes. I use your site all the time. I don’t know what I used to cook before I found you!
Ah yum! I am so glad you are loving this recipe and it turned out great for you 🙂
I loved this recipe! I just think that there was too much salt added to the sauce. I only added half a teaspoon when it called for 3/4 and it was still too salty. I’d recommend 1/4 teaspoon or skipping it because the parmesean is salty on its own.
I found this recipe a little bland. Good comfort food.
So sorry to hear that. You can always adjust the seasonings per your preference!
Super tasty! Loved this recipe and it was really easy to come together. I am dairy-free so made some subs: almond milk, dairy-free butter, nutritional yeast for Parmesan. Super soothing, filling and satisfying meal 🙌 thank you ~
Excellent! So glad you enjoyed this recipe and it turned out great ❤️
This is great comfort food, but we found it a little bland.
So sorry to hear that, did you change up any of the seasonings?