INGREDIENTS
1 lb
Ground beef
1
Green bell pepper
8 oz
Mushrooms
1
Yellow onion
1 cup
Beef broth
2 tbsp
Ketchup
1 tbsp
Worcestershire sauce
1/2 tsp
Black pepper, fresh ground
1 tbsp
Cornstarch
1/2 tsp
Kosher salt
6
Hamburger buns
2 tbsp
Butter
6
slices Provolone cheese