Bring a large pot of salted water to a boil and cook the pasta according to package directions. Drain and set aside.
Meanwhile, in a large oven-safe skillet or a Dutch oven brown the ground beef, remove the cooked beef, and set aside.
Add the oil to the pan along with the onion, green pepper, and mushrooms, and cook over medium heat until the veggies start to soften. Sprinkle the flour add the butter and mix until the veggies are coated with the flour and the butter is melted.
Add the beef broth, mixing well to avoid clumps. Followed by Worcestershire sauce. Add the oregano, salt, and pepper, bring the mixture to a simmer, and allow to thicken slightly.
Add the heavy cream and continue to simmer until the desired thickness is reached. Turn the heat down, add the shredded pepper jack cheese, and stir until melted.
Add the pasta and beef to the sauce mixture and stir to coat everything. Remove from heat, sprinkle the top with the torn provolone, and then broil for 2-3 minutes to melt the cheese.
Serve immediately