Sprinkle steak with salt and pepper. In a large skillet, heat 2 teaspoons oil over medium-high heat. Add steak; cook 5-7 minutes on each side or until meat reaches desired doneness (for medium-rare, a thermometer should read 135°; medium, 140°; medium-well, 145°). Remove from pan., In same skillet, heat remaining oil over medium heat. Add onion; cook and stir 4-5 minutes or until tender. Add jalapeno and garlic; cook 2 minutes longer. Stir in salsa, cilantro, lime juice and pepper sauce; heat through., Thinly slice steak across the grain; stir into onion mixture. Serve in tortillas; top as desired.