Heat a large skillet over medium high heat. You'll want to use a skillet that can handle a higher heat. I used my cast iron for this. Add vegetable oil to the skillet. When the skillet and oil are hot, add the peppers, onions, and mushrooms. Sauté until the onions begin to caramelize and peppers soften.

Push the vegetables to the side of the skillet and add the shaved beef. Season with salt and pepper as desired. Add Worcestershire sauce, if using. Sir fry the beef until cooked through.

Stir to combine vegetables and beef together.

Take a soft flour tortilla shell and add any desired condiment. Line with a few slices of provolone cheese. Add the beef and veggie mix on top of the cheese. Top with more cheese if desired and wrap it up. Allow the wrap to rest 5 minutes to allow the cheese to melt.