Cook the beef Add the shaved steak to a large sauté pan. Cook over medium‑high heat for 4–5 minutes.

Add vegetables Stir in the diced onions and peppers. Continue cooking until the beef is fully cooked.

Drain Drain any excess fat from the pan, then return the pan to the stove.

Add seasonings & gravy Pour in the 1 cup of water, then add the gravy mix, garlic powder, onion powder, salt, and pepper. Cook, stirring often, until the liquid has fully reduced and no moisture remains in the bottom of the pan.

Remove from heat Take the pan off the burner.

Add mayo & cheese Stir in the mayonnaise and shredded cheese until everything is well combined and melted.

Serve Spoon the mixture onto sub buns. Add extra mayo, peppers or additional cheese if you like. Enjoy.