Ingredients:
2 tablespoons butter
1 small yellow onion diced
1 small green bell pepper diced
8 ounces brown mushrooms minced
1/2 teaspoon Kosher salt
1/2 teaspoon fresh ground black pepper
2 pounds lean ground beef 80/20 or 85/15
2 tablespoons ketchup
2 tablespoons Worcestershire sauce
2 eggs
1 cup panko breadcrumbs
8 ounces Provolone Cheese Slices
Instructions: