Ingredients:
- 1 lb rigatoni pasta
- 2 tablespoon olive oil
- 1 yellow onion, diced
- 3 cloves garlic, minced
- 1 lb Italian sausage
- 1 (1 lb) can tomato puree
- 1 ½ teaspoons salt
- 1 teaspoon black pepper
- 1 teaspoon oregano
- 2 1/2 cups shredded mozzarella cheese, divided
- ½ cup parmesan cheese, shredded
