Cook the cheese tortellini according to package instructions, about 3-5 minutes in boiling salted water until al dente.

In a large skillet, heat 2 tablespoons of olive oil over medium-high heat. Add the thinly sliced beef sirloin, cooking for about 5 minutes until browned. Remove beef from skillet and set aside.

Using the same skillet, add chopped green bell pepper, diced onion, and minced garlic, sautéing for 5-7 minutes until softened.

In a separate saucepan, melt 2 tablespoons of butter over medium heat. Whisk in 2 tablespoons of all-purpose flour, cooking for about 1 minute until bubbly.

Gradually pour in 2 cups of whole milk while whisking. Continue stirring for about 3-4 minutes until the mixture thickens.

Reduce heat to low and add 1.5 cups of shredded provolone cheese and 0.5 cups of grated parmesan cheese, stirring until melted and smooth.

Add the cooked tortellini, beef, and sautéed vegetables into the cheese sauce, folding gently to combine.

Serve immediately, garnishing with fresh parsley or extra parmesan if desired.