A hearty mashup of Philly cheesesteak and sloppy joes: seasoned ground beef with peppers, onions and savory sauce, piled onto toasted hoagie buns and topped with melty provolone.
Heat a large skillet over medium-high heat and add the vegetable oil. When the oil shimmers, add the sliced onion and bell pepper and cook until softened, about 5 minutes.
Push the vegetables to the side of the skillet and add the ground beef. Cook, breaking it up with a spoon, until browned and no longer pink, about 6 to 8 minutes.
Stir the mushrooms and minced garlic into the beef and vegetables and cook for 2 more minutes until fragrant.
Add ketchup, beef broth, Worcestershire sauce, brown sugar, salt and pepper. Stir to combine and simmer for 5 minutes until the sauce thickens slightly.
Taste and adjust seasoning. Reduce heat to low and evenly layer provolone slices over the meat mixture, allowing the cheese to melt for 1 to 2 minutes.
If desired, spread butter on the hoagie buns and toast them in a separate skillet or under a broiler until golden.
Spoon generous portions of the cheesy sloppy steak mixture onto toasted buns and serve immediately.
Notes
Make ahead: the meat mixture can be refrigerated for up to 3 days and reheated gently. For a lighter version use lean ground sirloin and reduced-sugar ketchup.