Bring a large pot of salted water to a boil and cook tortellini according to package directions until al dente.
Drain tortellini and toss with 1 tablespoon olive oil; set aside.
Heat 1 tablespoon olive oil in a large skillet over medium-high heat.
Add beef, onions, and green bell pepper; sprinkle with Italian seasoning and cook, stirring frequently, until beef is browned and vegetables are tender.
Season with salt and pepper, then remove from heat and set aside.
In a medium saucepan, melt butter over medium heat and whisk in flour to form a roux.
Gradually add milk while whisking constantly, cooking until sauce thickens.
Lower heat and stir in shredded provolone cheese and Italian seasoning until smooth and melted.
Season sauce with salt and pepper to taste.
Add cooked tortellini and provolone sauce to the skillet with cheesesteak filling; gently toss to coat evenly.
Warm through on low heat then serve immediately, optionally garnished with extra provolone and Italian seasoning.