Cheesy Beef and Macaroni Casserole

Ingredients:
– 1 pound ground beef
– 1 small onion, finely chopped
– 2 cloves garlic, minced
– 1 teaspoon Italian seasoning
– 1/2 teaspoon salt
– 1/2 teaspoon black pepper
– 2 cups marinara sauce
– 2 cups uncooked elbow macaroni
– 2 cups shredded mozzarella cheese
– 1 cup shredded cheddar cheese
– 1/2 cup grated Parmesan cheese
– 2 cups heavy cream
– 2 tablespoons butter
– 2 tablespoons all-purpose flour
– Fresh parsley, chopped (for garnish)

Instructions: