Philly Cheese Steak Meatballs

Name: Philly Cheese Steak Meatballs
Cuisine: American
Ingredients: Olive oil; 1 pound ground beef; 1 bell pepper (I used half green, half red, diced small); 4 oz mushrooms (chopped small); 1 cup onions (diced small); 2 cloves garlic (minced); 1 egg; 2 tbs milk; 1 tbs Worcestershire sauce; 1 cup plain bread crumbs; 1/2 cup Parmesan cheese; 1 tsp pepper; 1/2 tsp salt; 2 tbs butter; 2 tbs flour; 1 cup milk (any kind); 1/2 cup beer (what ever kind you like); 1/2 tsp pepper; pinch of salt; 1/4 tsp garlic powder; 6 oz provolone cheese (I used slices)