Creating One Pot French Onion Pasta is simple when you follow these easy steps:

1. Heat the Oil and Butter: In a large pot, heat the olive oil and butter over medium heat until melted.
2. Caramelize the Onions: Add the sliced onions along with the sugar. Cook for about 10-15 minutes, stirring frequently until the onions are caramelized and golden brown.
3. Add the Broth and Seasonings: Pour in the beef broth and add thyme, salt, and pepper. Bring to a simmer.
4. Incorporate the Pasta: Add the pasta to the pot. Stir well to ensure the pasta is submerged in the broth.
5. Cook the Pasta: Cover the pot and let it cook for about 10-12 minutes, stirring occasionally, until the pasta is al dente and most of the liquid is absorbed.
6. Add the Cheese: Remove the pot from heat and stir in the Gruyère and mozzarella cheese until melted and creamy.
7. Serve and Garnish: Spoon the pasta into bowls and garnish with fresh parsley if desired.

These straightforward steps will lead you to a deliciously rich One Pot French Onion Pasta that you’ll want to make again and again!