Follow these simple steps to create your One-Pot French Onion Pasta:

1. Sauté Onions: In a large pot, melt the butter over medium heat. Add the sliced onions and a pinch of salt. Cook, stirring occasionally, until they are caramelized, about 15-20 minutes.
2. Add Garlic: Once the onions are golden brown, stir in the minced garlic and cook for an additional minute until fragrant.
3. Pour in Broth: Add the beef or vegetable broth, dried thyme, bay leaf, and bring the mixture to a boil.
4. Cook Pasta: Stir in the pasta, ensuring it is submerged in the broth. Reduce the heat to a simmer and cover the pot. Cook according to the pasta package instructions, usually about 10-12 minutes.
5. Add Cream: Once the pasta is cooked and most of the liquid is absorbed, stir in the heavy cream. Remove the bay leaf and adjust seasoning with salt and pepper.
6. Incorporate Cheese: Mix in the grated Gruyère cheese until melted and creamy.
7. Serve: Remove from heat and garnish with fresh parsley before serving.

These steps will guide you effortlessly through the cooking process, ensuring a delicious outcome every time.