In a medium saucepan on the stovetop, saute the diced onion over medium-high in a couple of drizzles of olive oil. Season with salt and black pepper to your taste. Saute until the onion softens and is beginning to brown, then add the sliced peppers.
Saute for 2-3 minutes, then add the minced garlic, ground beef and Italian sausage. Season the meat with salt and black pepper. Cook until no pink remains and the sausage and ground beef have browned. Drain all excess fat from the pan.
Add the Worcestershire sauce, pizza sauce, Italian seasoning, dried oregano and crushed red pepper flakes. Stir well, then cook for another 6-8 minutes until heated through.
Set the oven on the broil setting. Butter and lightly toast the hoagie rolls.
Fill sub rolls with loose meat and top with two slices of provolone or mozzarella cheese.
Return to the oven to melt the cheese.
Serve immediately.
Notes
Cheese: You can top these loose meat hoagies using any flavor of cheese that you enjoy or have on hand. Mozzarella works equally as well as provolone. You could also use cheddar, colby jack or monterey jack cheese if that's your jam.
Bell Peppers: You can adapt using any color or variety of bell peppers that you enjoy. You could use poblano pepper in place of green pepper, for spice.
Calabrian Chiles: You could use 1-2 teaspoons of Calabrian chiles in place of red pepper flakes.