Marinate the steak: Place the steak in a resealable bag. In a bowl, mix about ½ the packet of fajita seasoning, lime juice, and ¼ cup olive oil. Pour the marinade over the meat and make sure it completely coats the steak. Marinate in the fridge or cooler for at least 2 hours, up to 24 hours.* I prefer to do this step at home.
Slice the peppers into strips. Slice the onion. In a bowl, mix the peppers and onions with a drizzle of olive oil and the remaining fajita seasoning.
Cook the veggies in a cast iron pan over a flame.** Mix frequently until they become slightly charred and tender, but not mushy. Depending on your fire, this should take around 5-10 minutes. You might need to do this in two batches so you don't overcrowd the pan.
Once the veggies are done, remove them from the heat. They should stay warm for a while in the cast iron pan while you cook the steak.
Cook the steak on the grill over high heat for about 5 minutes on each side until medium-rare or medium. Remove the steak from the heat and let it rest on a cutting board.
Lastly, heat your tortillas on the grill and prepare the cilantro, shredded cheese, and sour cream.
Slice the steak into thin strips. Assemble the tortillas with steak, veggies, and all the toppings. Enjoy!
