Originally based on this recipe, though I was out of cumin. Whoops. Also, we grilled it instead of pan-frying.
Ancho-Rubbed Flank Steak
1 tsp kosher salt
1 tsp brown sugar
1 tsp ground ancho chile powder
Dash of freshly ground black pepper
1 (2-pound) flank steak, trimmed
2 bell peppers, sliced into strips
1 medium onion, thinly sliced
Combine first 4 ingredients in a small bowl; rub evenly over both sides of steak. Let rest for 1 hour.
Preheat grill to 400ºF. Grill flank steak 10 minutes, turning once halfway thru the cooking time, or until steak is medium. Let rest 10 minutes before cutting.
Meanwhile, place onions and pepper strips on the grill pan and squeeze half the lime over them. Grill 5 minutes, stirring occasionally, until veggies are done. Remove from grill and squeeze the remaining lime half over them.
Slice flank steak into strips across the grain. Serve with grilled veggies, warmed tortillas, cheese, salsa and other fixings for fajitas.