Mix diced tomatoes and coriander in a bowl and set aside. In another bowl combine the mashed avocado with 2 tablespoons of lime juice and set aside as well. Make sure you mix the avocado into the lime juice well, or it will brown.
Combine the thinly sliced steak with the fajita seasoning and 1 tablespoon of the oil in a bowl. Spin until well coated. Heat the remaining oil on a frying pan on high heat. Add the red onion, garlic, capsicum and stir for about 5 minutes or until the onion is golden and soft. Move to a bowl and cover to keep warm.
Reduce the heat to medium-high and cook the steak in batches, each for a few minutes, until cooked to your liking. Once cooked, bring together the steak, onion mixture and the rest of the lime juice in a bowl.
At the same time heat the tortillas as per the instructions on the pack. Serve the tortillas with the tomato mixture, avocado, and beef slices. Top with sour cream and additional avocado.
Recipe from stayathomemum.com.au