Cook the spaghetti squash. I use my air fryer and follow these directions for cooking the squash. The post also includes instructions for roasting spaghetti squash in the oven.Using a fork, gently shred the pulp from the inside of the squash and set aside.
Preheat the oven to 375˚F to bake the casserole when assembled.
On top of stove, heat the olive oil in a large skillet over medium heat. Add the onion, red bell pepper, and poblano pepper. Sauté until tender, about 5 minutes. Add the garlic and cook until fragrant, about 1 minute.
Add the spinach to the skillet and season with the nutmeg, salt, and pepper. Cook and stir the mixture until the spinach is wilted, about 3 minutes.
Gently stir in the cream cheese in chunks until melted. Add the cooked spaghetti squash and stir until combined.
Pour the mixture into an 8" X 8" casserole dish and top with the mozzarella and parmesan cheese. Bake at 375 degrees for 30 minutes, or until bubbly and the cheese is lightly browned.
Remove from the oven to a cooling rack for 10-15 minutes before serving if you want to cut the casserole into squares like a lasagna.
Notes
The Wimpy Vegetarian does not claim to be a registered dietician or nutritionist. Nutritional information shared on this site is only an estimate. We recommend running the ingredients through an online nutritional calculator if you need to verify any information.Ingredient Notes
Peppers - I used a combination of red bell pepper and poblano chile pepper for a little heat, but you can just use red bell peppers if that's your preference.
Yellow onion - white onion works well in this recipe too, but red onion is too sweet.
Baby spinach - I used pre-washed baby spinach in a plastic container to make it super easy. If you use more mature spinach, I recommend you slice off the leggy stems, and coarsely chop before adding to the casserole.
Cheeses - cream cheese is mixed into the casserole, and a mixture of mozzarella and Parmesan cheese tops the casserole. I used mozzarella cheese in a large round package, that was pre-sliced. This eliminated any cheese grating.