Step 1: In a large skillet, heat the olive oil over medium-high heat. Once the oil is hot, add the ground beef to the skillet. Cook the beef, breaking it up with a spoon, until it’s browned and cooked through, about 5-7 minutes. Once done, drain any excess fat if needed and set the beef aside.

Step 2: In the same skillet, add the chopped onion. Cook for about 2-3 minutes until the onions are soft and translucent, stirring occasionally to prevent burning.

Step 3: Add the minced garlic to the skillet and cook for an additional 30 seconds, or until fragrant. Be sure not to burn the garlic, as it can become bitter.

Step 4: Pour in the beef broth, heavy cream, Worcestershire sauce, Dijon mustard, dried thyme, salt, and pepper. Stir well to combine all the ingredients, and bring the mixture to a simmer. Let it simmer for about 3-5 minutes to allow the flavors to blend.

Once the tortellini is cooked, stir in the sour cream and let the sauce simmer for another 2-3 minutes until it thickens slightly. Garnish with chopped parsley and a sprinkle of Parmesan cheese, if desired. Serve immediately and enjoy your delicious one-skillet beef stroganoff tortellini!