"Look in the precut refrigerated produce section for a blend of sliced multicolored peppers. If starting from whole peppers, use about 2 medium peppers in each color (this step can also be done ahead). Fajita steak, or thinly sliced flank steak, is a relatively new addition to the meat counter. It’s ideal for quick cooking, especially in stir-fries. If you can’t find it, freeze a 12-ounce flank steak for about 5 minutes before slicing so the meat is easier to work with. Warm the tortillas in a skillet or right on the burner of your stove over medium heat...."