Heat your oven to 375°F (190°C). Brush off the top edge of the bread loaf by slicing it lengthwise and carefully scoop out the middle, keeping the walls about an inch thick. Save the bread bits for another use like croutons.
Warm the olive oil or butter in a pan over medium-high heat. Toss in the sliced onion and peppers, cooking them down until they soften and start to brown lightly, about 5 to 7 minutes.
Add the minced garlic to the veggies and cook it for about a minute until fragrant.
Add the steak strips to the pan, seasoning with salt, black pepper, and Worcestershire sauce. Cook until the meat is nicely browned and just done.
Brush the inside of your hollowed bread with the melted butter.
Layer half of the shredded cheese evenly on the bottom of the bread.
Spoon the cooked steak and vegetable mixture evenly over the cheese.
Top the filling with the rest of the shredded cheese.
Place the stuffed bread on a baking sheet and bake in the oven for 12 to 15 minutes, until the cheese melts and becomes bubbly.
If you prefer a nicely browned top, switch to broil and cook for an extra 1 to 2 minutes carefully.
Brush the crust edges with additional melted butter and sprinkle freshly chopped parsley over the loaf.
Cut the loaf into thick slices and serve the cheesy philly cheesesteak garlic bread warm.
