Classic Tex Mex fajitas consist of juicy strips of steak combined with colorful bell peppers and onions, all wrapped up in a warm tortilla. A bit of fresh jalapeño pepper will give the fajitas a little bit of firepower.
Slice the sirloin steak into thin strips, cutting across the grain of the meat. Slice any long slices in half.
Heat the canola oil in a heavy skillet over high heat and cook the meat for about 4 minutes, or until it's just barely pink in the middle. Move it to a plate and set it aside.
Spoon the fajita mixture into warm tortillas, and serve with salsa, sour cream or other toppings.