Chicken Parmesan Spaghetti Squash Casserole
If you came over on a Tuesday, there is a pretty good chance you would find this bubbling away in my oven while I try to remember where I left the grater. The first time I made Chicken Parmesan Spaghetti Squash Casserole, I was honestly just trying to use up a spaghetti squash that had been rolling around my counter like a bored cat. Turned out my family asked for seconds, then thirds, and I had to pretend I was full so everyone else could eat. Relatable, right?
Also, quick story. I once set the squash to roast and then wandered off to fold laundry. Came back to that loud ping a sheet pan makes when it warps, nearly jumped out of my skin, laughed, and kept going. Cooking is a wild ride sometimes, but we love it.
Why you will love this, or at least want to try it
I make this when I want that Chicken Parm comfort without the full deep fry situation. It feels lighter, but still cheesy and saucy in that big cozy way. My crew goes a bit bananas for the crispy little bits on top, and I secretly love that the squash strands soak up the marinara like tiny noodles pretending to be pasta. It does the job.
If I am being honest, I used to dread scraping squash strands because it felt fussy. Then I realized if I let it cool a little first, it practically falls out. Problem solved. Mostly. And on nights when I am out of breadcrumbs and patience, I just coat the chicken with grated parmesan and a smidge of almond flour and call it good. Works a treat.
Ingredients I keep on hand
- 1 medium spaghetti squash, about 1.2 to 1.5 kg
- 2 chicken breasts, thinly sliced or pounded to about 1 cm thick
- 1 cup marinara sauce, plus a splash more if you like it extra saucy
- 1 cup shredded mozzarella, loosely packed
- 1/2 cup grated parmesan, divided
- 1 cup breadcrumbs or panko, regular or gluten free
- 1 egg, beaten
- 2 tablespoons olive oil, plus more for the squash
- 2 cloves garlic, minced
- 1 teaspoon Italian seasoning, or just a pinch of oregano and basil
- Salt and black pepper, to taste
- Fresh basil or parsley, a handful, for serving
Substitutions I actually use:
- I sometimes use rotisserie chicken when I am in a hurry. Toss it with a little marinara and parmesan and it is great.
- Almond flour can stand in for breadcrumbs if you want it grain free. My grandmother always insisted on Brand X breadcrumbs, but honestly any version works fine.
- Provolone slices instead of mozzarella when I have them, it melts beautifully.
- Jarred marinara is fine. I like this round up of good ones at The Kitchn.
How I actually cook it, step by stepish
- Heat the oven to 200 C. Halve the spaghetti squash lengthwise and scoop out the seeds with a spoon. Rub the cut sides with a little olive oil, sprinkle with salt and pepper, and place cut side down on a lined sheet pan. Roast 35 to 45 minutes until the skin gives when pressed.
- While the squash roasts, set up chicken. Season the breasts with salt and pepper. Put the beaten egg in one shallow bowl and the breadcrumbs mixed with half the parmesan and Italian seasoning in another.
- Dip chicken in egg, then in the breadcrumb mix. Heat 2 tablespoons olive oil in a large skillet over medium heat and cook chicken 3 to 4 minutes per side until golden. It will finish in the oven, so do not stress if the center is slightly under at this point.
- When the squash is cool enough to handle, scrape the strands into a big bowl with a fork. This is where I usually sneak a taste, purely for science.
- Stir in the marinara, garlic, a pinch of salt, and a handful of mozzarella. If it looks a bit loose, actually, I find it works better if you add a spoonful more parmesan to tighten it up.
- Transfer the squash mix to a lightly oiled casserole dish, something around 23 by 33 cm. Nestle the browned chicken on top. Spoon a little extra marinara over the chicken. Scatter over the remaining mozzarella and parmesan. If you like extra crunch, add a small handful of dry breadcrumbs over the cheese.
- Bake 15 to 20 minutes until bubbly and the cheese is lightly browned. If you want more color, pop under the broiler for 1 to 2 minutes. Do not wander off like I did once. It goes quick.
- Let it rest 5 to 10 minutes before serving. I know waiting is annoying, but it sets up and slices nicer. And yes, it always looks a bit messy at this stage, do not worry, it settles.
Curious about internal temp for chicken safety If you are checking, you are looking for 74 C. Here is a handy chart from FoodSafety.gov. On second thought, I often go by the color and juices if my thermometer has vanished, which it does, probably hiding in the utensil drawer like a shy turtle.
Little notes I wish I knew sooner
- Salt the squash before roasting and let it sit cut side up for 10 minutes. Dab away any moisture, then roast. It makes the strands less watery.
- If your marinara is very tart, a tiny pinch of sugar smooths it out. Or a splash of cream, which is lovely and not traditional, I know.
- Breadcrumbs brown faster than you think, so if they are getting too toasty, tent with foil for the last few minutes. I once forgot, the top was more enthusiastic than I wanted, still tasty though.
Variations I have tried
- Buffalo style: swap marinara for a mix of hot sauce and a touch of butter, use blue cheese crumbles. My friends went mad for it.
- Veggie twist: skip the chicken and add roasted mushrooms and spinach. Extra mozzarella does the heavy lifting here.
- Low effort night: toss cooked shredded chicken directly with sauce and parmesan, skip breading entirely. Different vibe, still comforting.
- The one that did not work: pesto instead of marinara. It went kind of oily and lost its charm. Maybe I used too much, but I would not do that again.
Gear that helps
- A sturdy sheet pan for roasting the squash. If yours warps, no biggie, it still cooks fine.
- A large skillet for browning chicken. Cast iron makes a nice crust, but any pan does the trick.
- A meat thermometer is great for peace of mind. Or just slice and peek if you must, I have done that plenty.
- If you want a quick method for squash, this guide from Serious Eats is spot on.
If you do not have a casserole dish, use a big oven safe skillet. I even used a loaf pan once, it looked funny but tasted grand.
Storing and reheating
Fridge: cool completely, then cover. It keeps 3 to 4 days, though honestly, in my house it never lasts more than a day. Reheat at 180 C for about 15 minutes, or just microwave in short bursts, stirring halfway so the cheese melts evenly.
Freezer: you can freeze leftovers in portions. Wrap well. Thaw in the fridge and reheat gently so it stays creamy. I think this tastes better the next day, but maybe that is just me.
How I like to serve it
I shower it with torn basil and a squeeze of lemon for brightness. A simple green salad on the side, maybe garlicky broccoli if I am feeling fancy. My kids dunk pieces in extra marinara like it is a sport. We also have a tiny family tradition of eating the first scoop straight from the corner because the corners are the crispiest. Do yall do that too
Pro tips learned the hard way
- I once tried rushing the squash roasting and pulled it form the oven at 25 minutes. The strands were crunchy in a bad way, so yeah, give it time.
- Do not overload with sauce. I did that and turned it into a tasty but slightly soupy situation. A cup is usually plenty for the base, then spoon a bit on top.
- If you bread the chicken, press the crumbs on firmly. I skipped that step once and they slid off like a sweater on a smooth chair.
Questions you might ask
Can I cook the squash in the microwave
Yes, poke it a few times, microwave 5 minutes to soften, then halve and finish in the oven. Or microwave in short bursts until tender. Oven gives better flavor, but the quick route works.
What if I only have thighs
Go for it. Slice into strips, bread and brown. They stay juicy. Cooking time might be a couple minutes longer.
Is this gluten free
It can be. Use gluten free breadcrumbs or almond flour, and make sure your marinara is gluten free. Easy fix.
Can I make it ahead
Yes. Assemble, cover, and chill up to a day. Bake from cold at 180 C for a bit longer until hot and bubbly. I tend to think it sets even nicer.
Do I need to squeeze the squash dry
If it seems very wet, give it a quick squeeze in a clean towel. Usually, letting it steam off for a few minutes is enough. No need to go overboard.
What cheese is best
Mozzarella for melt, parmesan for salty bite. Provolone is lovely. A cheeky bit of fontina melts like a dream. Use what you have, mate.
Alright, that is the casserole. It is saucy, a little cheesy, and very friendly to weeknights. If you try it, cheers and let me know how it goes. Unless I am chasing that runaway squash again, in which case I will reply in a minute.
Ingredients
- 1 medium spaghetti squash (about 2 to 3 lb)
- 2 tablespoons olive oil, divided
- 1 pound cooked boneless skinless chicken breasts, shredded or cubed (rotisserie chicken works)
- 2 cups marinara sauce (homemade or store-bought)
- 2 cups shredded mozzarella cheese, divided
- 1/2 cup grated Parmesan cheese, plus extra for sprinkling
- 1/4 cup panko breadcrumbs (optional for topping)
- 2 cloves garlic, minced
- 1 teaspoon Italian seasoning
- Salt and freshly ground black pepper, to taste
- Fresh basil or parsley, chopped, for garnish
Instructions
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1Preheat the oven to 400°F (200°C). Slice the spaghetti squash lengthwise and scoop out the seeds. Drizzle cut sides with 1 tablespoon olive oil and season with salt and pepper. Place cut-side down on a baking sheet and roast for 35 to 45 minutes, until the flesh is tender and easily shredded with a fork.
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2While the squash roasts, combine the shredded cooked chicken, marinara sauce, minced garlic, Italian seasoning, and a pinch of salt and pepper in a bowl. Stir in 1/2 cup of the mozzarella and 1/4 cup of the Parmesan to incorporate.
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3When the squash is cool enough to handle, use a fork to scrape out the strands into a large bowl, discarding the skins. Toss the squash strands with the remaining 1 tablespoon olive oil and adjust seasoning as needed.
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4In a greased 9×13-inch baking dish, layer half of the spaghetti squash, then spread the chicken-marinara mixture evenly, and top with the remaining squash. Sprinkle the remaining mozzarella and Parmesan over the top. If using, mix panko breadcrumbs with a little olive oil and sprinkle over the cheese for extra crunch.
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5Bake the casserole at 375°F (190°C) for 20 to 25 minutes, until heated through and the cheese is melted. For a golden top, broil for 1 to 3 minutes, watching carefully to prevent burning. Let rest 5 minutes, garnish with fresh basil or parsley, and serve.
Approximate Information for One Serving
Nutrition Disclaimers
Number of total servings shown is approximate. Actual number of servings will depend on your preferred portion sizes.
Nutritional values shown are general guidelines and reflect information for 1 serving using the ingredients listed, not including any optional ingredients. Actual macros may vary slightly depending on specific brands and types of ingredients used.
To determine the weight of one serving, prepare the recipe as instructed. Weigh the finished recipe, then divide the weight of the finished recipe (not including the weight of the container the food is in) by the desired number of servings. Result will be the weight of one serving.
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