1. Boil water for pasta; add pasta and cook according to package directions, to desired consistency. Drain and set aside. Preheat oven to 375 degrees F.
2. In a large nonstick pan, heat olive oil over medium heat. Add onion and garlic and cook until translucent, about 2 minutes. Add mushrooms and peppers to the pan and cook until tender, about 4 minutes.
3. Season vegetables with red pepper and Italian seasoning. Add tomatoes, tomato paste, and water. Cook for 5 minutes.
4. In an oven-proof baking dish, combine, pasta, sauce, sausage, and 1/2 cup cheese. Top with remaining cheese. Bake for 5 minutes.
Source of recipe: I wrote the recipe.