Preheat the oven to 350 degrees.
Saute the onions and peppers in the oil in a skillet over medium heat until softened.
Add the ground beef, cooked onions and peppers, Worcestershire sauce, breadcrumbs, minced garlic, onion powder and salt and pepper to taste to a mixing bowl, and knead well to combine.
Shape half of the mixture into a loaf shape in either a loaf pan or baking dish.
Top with the provolone slices. Spread the remaining meat mixture over top of the other, and form it into a loaf, making sure the cheese is securely sealed inside.
Bake for 30 minutes. Remove, and top with the shredded cheese.
Bake another 15 minutes before serving.
Enjoy!¯