1. Bring a large pot of salted water to a boil. Cook the penne pasta until al dente, then drain and set aside. Reserve some pasta water if needed for the sauce.

2. In a large skillet over medium-high heat, brown the ground beef, breaking it up as it cooks. Once fully cooked, remove and drain excess grease.

3. In the same skillet, sauté the chopped onion for 3–4 minutes until translucent. Add garlic and cook for another 30 seconds until fragrant.

4. Return the cooked ground beef to the skillet. Stir in Italian seasoning, salt, pepper, and crushed red pepper flakes. Let everything cook together for 2 minutes.

5. Pour in the beef broth and bring to a simmer. Stir in the heavy cream and reduce heat to medium-low. Simmer for 5–7 minutes until slightly thickened.

6. Add shredded cheddar and mozzarella cheeses gradually, stirring constantly until melted into a smooth, creamy sauce.

7. Add the cooked pasta into the sauce and mix well. Use a splash of reserved pasta water if the sauce is too thick.

8. Garnish with fresh parsley and serve immediately while hot.