Creating your One Pot Creamy French Onion Pasta Bake is a simple process that yields remarkable results. Follow these easy steps:

1. Preheat Oven: Begin by preheating your oven to 375°F (190°C).
2. Sauté Onions: In a large oven-safe pot, heat the olive oil over medium heat. Add the sliced onions and cook for about 15-20 minutes, stirring occasionally, until they are golden brown and caramelized.
3. Add Garlic: Stir in the minced garlic and cook for an additional 1-2 minutes until fragrant.
4. Combine Pasta and Broth: Add the penne pasta to the pot, followed by the vegetable broth, heavy cream, thyme, salt, and pepper. Mix well.
5. Simmer: Bring the mixture to a gentle simmer and cook for about 8-10 minutes, or until the pasta is al dente, stirring occasionally to prevent sticking.
6. Add Cheese: Remove the pot from heat, then stir in the Gruyère and mozzarella cheeses until melted and creamy.
7. Bake: Transfer the pot to the preheated oven. Bake uncovered for 15-20 minutes or until the cheese is bubbly and golden brown.
8. Garnish: Remove from the oven and allow to cool slightly. Garnish with fresh parsley before serving for a pop of color.

With these steps, you’ll effortlessly create a creamy pasta bake that is both satisfying and delicious. Enjoy the aromatic blend of flavors wafting through your kitchen as you prepare this comforting dish!