Preheat your oven to 350°F (175°C).
In a skillet over medium heat, sauté the onions, bell pepper, and garlic until tender, about 5-7 minutes.
In a large bowl, combine the ground beef, sautéed vegetables, breadcrumbs, provolone cheese, eggs, Worcestershire sauce, salt, and pepper.
Transfer the mixture to a loaf pan and shape it into a loaf.
Spread ketchup over the top of the meatloaf for a flavorful glaze.
Bake for 60-70 minutes or until the internal temperature reaches 160°F (70°C).
Let the meatloaf rest for 10-15 minutes before slicing.