Pasta al Forno

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