5-Ingredient Steak Fajitas with Sweet Peppers & Onions

Skillet Steak Fajitas with Sweet Peppers & Onions. Recipe by Becky Duffett | Photo by Erin Kunkel. Whenever you run out of ideas, just fire up a cast-iron skillet, and sear off some steak and veggies. Juicy flank steak and sweet bell peppers are delicious on their own or folded into soft tortillas.