Preparing the Meat and Vegetables
Heat a large skillet over medium heat and melt the butter.
Add the chopped onions and bell peppers and cook, stirring frequently, for 6–7 minutes until they’re soft and fragrant. Avoid browning; we just want them tender.
Cooking the Sloppy Joe Filling
Push the vegetables to the side and add the ground beef. Use a wooden spoon to break the meat into small pieces. Cook for 5–6 minutes until the beef is fully browned.
Adding Cheese and Final Touches
Stir in the beef stock, ketchup, Worcestershire sauce, garlic powder, salt, and black pepper. Reduce the heat to low and simmer for 4–5 minutes, allowing the mixture to thicken slightly.
Stack 6 slices of provolone on a cutting board and cut them into 1/2-inch pieces. Stir these into the filling just before serving for extra cheesy goodness.
Assembling the Sloppy Joes
Toast the brioche buns until golden. Lay the remaining 6 provolone slices on the bottom halves of the buns.
Spoon the beef mixture on top and cover with the top bun. Serve warm.
Pro Tip: Leftover mixture keeps well in the fridge for 4–5 days and reheats nicely in a skillet with a splash of water or stock. You can also freeze it for up to 3 months—just thaw before reheating