Preheat your oven to 375°F (190°C).

In a medium skillet, heat 2 tablespoons of olive oil over medium heat. Add the diced green bell pepper and onion, sautéing for about 5 minutes until softened and fragrant.

In a large mixing bowl, combine 1 pound of ground beef, 1 cup of breadcrumbs, 1 beaten egg, ½ cup of milk, 2 tablespoons of Worcestershire sauce, 1 teaspoon of garlic powder, and season with salt and pepper to taste. Mix gently until just combined.

Take half of the meat mixture and press it into the bottom of a loaf pan. Layer 4 slices of provolone cheese over the meat, then spoon the sautéed onions and bell peppers on top. Finally, place the remaining meat mixture on top, sealing the edges.

Bake in the preheated oven for 45-50 minutes, until the internal temperature reaches 160°F (70°C).

In the last 5 minutes, add remaining provolone cheese on top and bake until melted and bubbly.

Allow to rest for 5-10 minutes before slicing. Garnish with fresh parsley if desired.