Preheat oven to 350F.
In a large skillet coated with nonstick cooking spray, cook the onions over medium-low heat for about 10 minute, until softened. Add the mushrooms and continue cooking for another 5-10 minutes, until they release their moisture. Add the garlic, chicken sausage, and crushed red pepper. Season with salt and pepper. Raise the heat a bit, and cook for another minute, until garlic is fragrant. Finally, add the spinach, a few handfuls at a time, stirring until wilted. Remove from heat.
In a bowl, mix together the spaghetti squash, egg, ricotta cheese, half of the grated pecorino romano, and Italian seasoning.
Lightly coat an 8"or 9" spring-form pan with cooking spray. Place half of the spaghetti squash mixture evenly on the bottom of the pan. Top with half of the vegetable mixture and half of the sauce. Repeat layers. Sprinkle remaining grated cheese on top of the sauce.
Cover tightly with foil and bake for 40 minutes. Remove foil and bake for another 5-10 minutes, until top is browned.
Let stand for 10 minutes, then un-mold and slice.
Recipe Notes
- Spaghetti squash can be roasted, microwaved, or slow-cooked prior to preparing the recipe. To roast the squash, preheat oven to 400F. Pierce the squash all over with a sharp knife and place in a baking dish with about 1" of water. Cook for one hour. Remove from oven and let cool. Cut the squash in half, scoop out the seeds, and then use two forks to remove the stringy flesh.
- Chicken sausage can be a great low-fat alternative to traditional pork sausage, but it's important to read the ingredients and nutrition facts. Try to choose one without unnecessary additives. As a rule of thumb, I read the ingredient list and only buy it if I can easily pronounce all the words and know what everything is. For this recipe, I used Sam's Club Spinach and Asiago flavored chicken sausage.
- Similarly, with jarred marinara sauce, I look for a brand with as few ingredients as possible and no added sugar. For this recipe, I used Classico Tomato and Basil Pasta Sauce.