Preheat your oven to 375°F (190°C).

In a large skillet over medium heat, add the ground beef and cook until browned, about 5 minutes. Add the chopped onion and minced garlic, sauté for another 5-7 minutes until the onion is translucent.

Stir in the crushed tomatoes, beef broth, Italian seasoning, salt, and pepper. Let simmer for about 10 minutes until thickened.

Add the cheese tortellini and half of the mozzarella cheese to the sauce, folding gently. Stir until well coated.

Transfer the mixture to a large baking dish and spread evenly. Sprinkle the remaining mozzarella cheese on top.

Bake in the preheated oven for 25-30 minutes until the cheese is bubbly and golden brown.