Preheat oven to 400 degrees. Spray a large pan or nonstick skillet with cooking spray.
Season beef with salt and pepper, cook over medium high heat, stirring throughout, until cooked through. Transfer to a bowl. Add onions, peppers, and mushrooms (optional) and cook, stirring throughout until onions are translucent. Add garlic cook another minute or so til garlic is fragrant. Add beef back to pan and stir to combine.
Slice hoagie rolls down the center the long way. Spread mayo onto both sides of the rolls. Place 2 slice of pepperjack cheese on one side of each roll. Top with beef, peppers, and onions (and optional mushrooms). Place open rolls in the oven for about 3-5 minutes until cheese is melty. Serve warm and enjoy!
Notes
Flavor tip: Swap out the pepperjack for sharp cheddar.