Slice the steak into 1cm wide strips. In a large, shallow dish, combine the lime juice, tequila, chilli powder, oregano, cumin and pepper. Add the steak strips and the spring onions and toss them well. Let them marinate for 20 mins at room temp.
Combine the salsa ingredients in a bowl; let the salsa stand for about 15 minutes to blend the flavours.
Stack the tortillas and wrap them in aluminium foil. Warm them in a preheated oven for 10 mins (180.C, 350.F or mark4). Meanwhile, cook the steak strips in the centre of the grill for 1 min per side; the steak should be medium rare and the spring onions lightly charred. Cut the steak strips into pieces about 2.5cm ling.
To serve, place some steak onto a tortilla, add some lettuce and a spring onion to each tortilla, then spoon salsa over the top.
