Do me a favor and don't use packaged fajita seasoning blends. You don’t need them when making this recipe – this marinade is 100% natural and delicious.
In a small bowl combine garlic, salt, chili powder, cumin, black pepper, lime juice, and 2 tablespoons of the oil. Pour marinade over steak. Seal bag and turn to coat. Marinate in the refrigerator about 1 hour, turning bag once or twice.
In a large cast iron skillet, add 1 tablespoon of the oil on medium-high heat. Place the whole slice of marinated beef on the skillet and cook for about 4-5 minutes per side for medium-rare, or to your desired level of doneness. Remove to a cutting board and tent with foil to rest.
Heat 1 tablespoon of the oil in large skillet on medium-high heat. Add bell peppers and onion; cook and stir 3 to 5 minutes. Remove from skillet.
In the same skillet add 1 tablespoon of the oil on medium-high heat and add meat; cook and stir 3 minutes or until no longer pink. Remove from skillet.
Fill warm tortillas with steak, peppers, and onion. Top with your favorite toppings.
Notes
Nutrition facts do not include tortilla or any toppings. Storage & Heating Instructions
Refrigerated - Cooked steak fajitas and veggies can be kept in an airtight container in the fridge for up to 5 days. For uncooked marinated steak, try not to exceed 24 hours in the marinade—the acidity from the lime juice can make the meat kinda mushy.
Frozen - You can also store fajita leftovers in the freezer. I recommend using freezer-safe bags. It will keep well for up to 3 months.
Reheating - Allow fajita meat and veggies to defrost overnight in the fridge if needed, then warm in a skillet over medium heat. I don’t recommend microwaving, as steak can get rubbery using this method.