Start by heating a large skillet over medium-high heat and add a drizzle of olive oil to cover the bottom.

Once the oil is hot, sauté the sliced onions and bell peppers for about 3-5 minutes until tender and slightly translucent. If using mushrooms, add them at this point and cook for an additional 3 minutes.

Push the vegetables to one side of the skillet and add the ground beef to the empty side. Break the beef apart with a spatula and cook until no longer pink, about 5-7 minutes.

Mix the browned beef with the vegetables and stir in the garlic powder, Worcestershire sauce, salt, and black pepper. Cook for another 2 minutes to let flavors combine.

Lower the heat to low and place a slice of cheese over the beef and vegetable mixture. Cover with a lid and let sit for 2-3 minutes to melt the cheese.

While the cheese melts, slice the hoagie rolls lengthwise without cutting all the way through.

Once the cheese has melted, fill each hoagie roll with the beef and vegetable mixture generously.

Toast the filled rolls lightly in the skillet for added texture before serving.