Combine all of the burger ingredients in a large bowl.
1 pound ground beef, 1 pound ground Italian sausage, 1 large egg, 1 teaspoon Italian seasoning, ½ cup Italian breadcrumbs, ½ teaspoon kosher salt
Form into 6 patties.
Preheat the grill to medium heat (about 350-375°F).
Heat the olive oil in a skillet over medium heat (on the stove or grill).
2 tablespoons olive oil
Add in the green peppers and onions and sprinkle with salt. Sauté for a few minutes until softened and the edges are browned. Transfer to a plate.
1 green pepper, ½ onion, ⅛ teaspoon kosher salt
Add the mushrooms to the pan and cook for a couple minutes until softened.
8 ounces cremini mushrooms
Grill the burgers for 4 minutes.
Flip the burgers. Then, top each burger with a slice of mozzarella cheese and cook for another 4 minutes.
6 slices low moisture mozzarella cheese
Place the burger on the bottom half of the bun. Then, add on a few spoonfuls of pizza sauce, 4 slices of pepperoni, and a pile of vegetables over the top.
1 cup pizza sauce, 24 slices pepperoni, 6 hamburger buns
Top with basil leaves and more pizza sauce before placing on the top bun and serving.
Fresh basil leaves