Step 1: Cook the Tortellini

1. Bring a large pot of salted water to a boil and cook the tortellini according to package instructions.
2. Drain the tortellini and set aside, reserving ½ cup of the pasta water for later.

Step 2: Prepare the Cheesesteak Mixture

1. In a large skillet, heat olive oil over medium heat.
2. Add the shaved beef and cook for 2-3 minutes until browned. Remove and set aside.
3. In the same skillet, sauté the onions and peppers until softened, about 4-5 minutes.
4. Stir in the minced garlic and cook for an additional minute. Season with salt and pepper.
5. Return the beef to the skillet, toss to combine, and set the mixture aside.

Step 3: Make the Provolone Sauce

1. In a medium saucepan, melt the butter over medium heat.
2. Whisk in the flour and cook for 1 minute to form a roux.
3. Gradually whisk in the milk, stirring constantly to prevent lumps. Cook until the mixture thickens, about 2-3 minutes.
4. Remove from heat and stir in the shredded provolone, garlic powder, Dijon mustard (if using), and a pinch of salt and pepper. Whisk until smooth and creamy.

Step 4: Combine Everything

1. Add the cooked tortellini to the skillet with the cheesesteak mixture.
2. Pour the provolone sauce over the top and toss everything together gently. If the sauce is too thick, use the reserved pasta water to loosen it to your desired consistency.

Step 5: Serve and Enjoy

1. Transfer to serving plates and garnish with fresh parsley, if desired.
2. Serve hot and enjoy the melty, savory goodness!