Preheat a large chargrill pan over medium-high heat.
Make the avocado salad by gently tossing all the ingredients together until well combined. Season to taste.
Sprinkle the steak with the spice mix on both sides to coat evenly, then spray lightly with oil. Char-grill for 1 minute each side or until just cooked and golden. Slice into 8 pieces, then transfer to a plate and cover loosely with foil to keep warm.
Spray the tortillas lightly with oil on both sides. Chargrill, in 2 batches, for 5 seconds each side or until heated and golden. Transfer to serving plates.
Top the tortillas evenly with the lettuce, steak, salsa and avocado salad. Serve.