Step 1: Preheat your oven to 400°F (200°C). This ensures your cheesesteak filling gets nice and hot while the vegetables roast perfectly.
Step 2: In a large skillet over medium heat, add the olive oil. Once hot, add the lean ground beef. Cook until browned, breaking it apart with a spatula as it cooks. This should take about 5-7 minutes.
Step 3: Stir in the softened cream cheese, steak seasoning, and Worcestershire sauce until fully combined. Cook for an additional 2-3 minutes until the cream cheese is melted and the mixture is creamy.
Step 4: While the beef is cooking, slice your bell peppers, mushrooms, and onion. Once the beef mixture is ready, transfer it to one side of the sheet pan.
Step 5: On the other side of the sheet pan, add the sliced mushrooms, bell peppers, and diced onion. Drizzle with a little olive oil and toss to coat. Season with salt and pepper to taste.
Step 6: Place the sheet pan in the preheated oven and bake for 15-20 minutes, or until the vegetables are tender and slightly caramelized.
Step 7: Remove the pan from the oven, and sprinkle the sliced or shredded Provolone cheese over the beef mixture. Return to the oven for an additional 5 minutes or until the cheese is melted and bubbly.
Step 8: While the cheese melts, slice your rolls and spread a little butter and garlic salt on each half. Toast them under the broiler for 1-2 minutes until golden brown.
Step 9: Spoon the cheesesteak mixture onto the toasted rolls, add a dollop of mayonnaise, and enjoy your Sheet Pan Philly Cheesesteak!