Slice the beef thinly against the grain. Dice the onions and bell peppers into uniform pieces.

Heat a large skillet over medium-high heat and add oil. Cook the sliced beef for 3–5 minutes until browned, then set aside.

In the same skillet, sauté the onions and bell peppers for 8–10 minutes until caramelized.

Combine the browned beef with the sautéed vegetables. Add Worcestershire sauce, minced garlic, and seasonings. Simmer for 5 minutes.

Reduce heat to low, top with cheese, cover, and melt for 2–3 minutes.

Toast the buns in a preheated oven at 350°F for 5 minutes until golden.

Assemble by spooning the beef mixture onto the toasted buns and serve immediately.