Cook Tortellini: Bring a large pot of salted water to a boil. Add cheese tortellini and cook according to package instructions for 3-5 minutes. Reserve ½ cup pasta water before draining.

Sear Beef: In a large skillet, heat olive oil over medium-high heat. Add the sliced beef in a single layer and sear for 2-3 minutes until browned. Flip and cook for another 1-2 minutes. Remove from skillet.

Sauté Vegetables: Add sliced onions and bell peppers to the same skillet. Sauté for 3-4 minutes until softened. Stir in minced garlic and cook for 30 seconds until fragrant.

Make Sauce: Add beef broth and Worcestershire sauce to the skillet, scraping up browned bits. Stir in Italian seasoning, then add heavy cream and provolone cheese, mixing until melted and creamy.

Combine: Return beef to the skillet and add drained tortellini. Toss until well coated in sauce. Simmer on low for 1-2 minutes to meld flavors.

Garnish & Serve: Adjust seasoning, then garnish with parsley and red pepper flakes. Serve hot.