combine chili powder, salt, ground cumin, garlic powder and cayenne pepper for fajita seasoning then cover flank steak in seasoning
cut up bell peppers
heat up skillet to medium high heat. You have a choice to use the olive oil or not. Depends if your pan is subject to sticking but if used understand olive oil will reach its smoking point
toss in seasoned steak in pan and cook to desired doneness. For medium I browned both sides about 3 minutes each then dropped the heat to medium for 4-5 minutes
After steak is done leave any juices in the pan. There shouldn't be too many. Here I do recommend the tablespoon of olive oil. Toss in cut up bell peppers and onions if desired
Cook on medium heat for 3-5 minutes depending on level of doneness you desire. I like mine soft with a small crunch.