1. Preheat your oven to 350°F (175°C) and prepare a greased loaf pan or line it with foil. In a large bowl, combine the ground beef, breadcrumbs, egg, milk, Worcestershire sauce, garlic powder, salt, and black pepper. Mix the ingredients until just combined.

2. In a skillet, heat the olive oil over medium heat. Add the diced green bell pepper and onion and sauté until softened, about 5 minutes. Allow the veggies to cool slightly before assembling the meatloaf.

3. Press half of the meatloaf mixture into the prepared pan. Top it with the sautéed vegetables, then arrange 4 slices of provolone cheese on top. Cover the filling with the remaining meatloaf mixture, pressing gently to seal the edges.

4. Bake the meatloaf uncovered for 45-50 minutes, or until the internal temperature reaches 160°F (71°C). In the last 5 minutes of baking, place the remaining 4 slices of provolone cheese on top and return it to the oven until melted and bubbly.

5. Let it rest for 5-10 minutes before slicing. Garnish with freshly chopped parsley and serve with your favorite sides.