Spaghetti Squash Casserole with Chicken

Step 1
Preheat the oven to 425 degrees F (220 degrees C).

Step 2
Drizzle cut sides of spaghetti squash with 1 tablespoon olive oil and season with salt and pepper. Place on a sheet pan with the cut sides down.

Step 3
Roast in the preheated oven until a fork easily penetrates the skin, about 30 minutes. Remove from the oven and set aside until cool enough to handle. Shred flesh with a fork until it resembles spaghetti noodles; transfer to a colander to drain for 20 minutes. Lower oven temperature to 350 degrees F (175 degrees C).

Step 4
While squash is draining, heat remaining olive oil in a skillet over medium heat. Add onion; cook and stir for 2 minutes. Stir in garlic and cook until fragrant, about 1 minute. Add ground chicken and season with salt and pepper. Cook until chicken is browned and crumbly with no pink remaining, 5 to 7 minutes. Remove from the heat and stir in spaghetti sauce.

Step 5
Transfer drained squash to a 9×13-inch casserole dish. Add sauce mixture, spinach, 1/2 of the mozzarella cheese and 1/2 of the Parmesan cheese; toss to combine. Sprinkle remaining cheeses over the top.

Step 6
Bake in the preheated oven until casserole is bubbling and cheeses have melted, about 20 minutes.