Preheat the oven to 350 degrees.
Boil the pasta according to the box instructions to al dente.
8 ounces Elbow pasta
In a large skillet, add the butter over medium heat and saute the onions until mostly transucent, about 5 minutes.
2 tbsp Butter, 1 small Onion
In a large skillet brown the ground beef (drain if too much fat), season with kosher salt and black pepper.
1 pound Ground Beef, 1/2 tsp Kosher salt, 1/4 tsp Black pepper
Add garlic, parsley, oregano and red pepper flakes, cook about 2 minutes.
2 cloves Garlic, 1 teaspoon dried Parsley, 1 1/2 teaspoons Oregano, 1/4 teaspoon crushed Red Pepper
Add the tomato sauce and crushed tomatoes, cook to warm through.
15 ounce Tomato sauce, 15 ounce can crushed Tomatoes
Mix the tomato meat mixture with the pasta, pour into a casserole dish.
8 ounces Elbow pasta
Top with the cheddar and mozzarella cheeses and bake for 35-45 minutes.
1/2 cup Sharp Cheddar cheese, 1/2 cup Mozzarella cheese
Let rest about 10 minutes before serving.