Place sliced steak in a shallow dish. In a small bowl combine lime juice, 3 tbsp. olive oil, fajita seasoning and salt. Pour half of the marinade over the steak and toss to evenly coat.
Heat 1 tbsp. olive oil in a large cast iron skillet or over medium-high heat and add onions and peppers. Cook, stirring frequently, until onions begin to soften and peppers are tender and slightly seared, about 8 minutes. Stir in corn and cook an additional 2 minutes. Remove vegetables from pan.
Wipe out the skillet and warm remaining tbsp. olive oil over medium-high heat. Add steak and cook 4-5 minutes until seared. Reduce heat, transfer vegetables back to the pan along with remaining marinade and cook an additional 2-3 minutes.
Lay out tortillas on a clean work surface and layer each with steak and vegetables, cheese and avocado. Roll into a wrap and enjoy!