Combine the oil, lemon juice, vinegar and some salt and pepper for the dressing.
Pull out a piece of cling film six times the width of the steak. Place the steak in the centre of one-half of the cling film, and fold the other half over it. Now, gently, using either a wooden mallet or a rolling pin, beat the steak out evenly until paper thin and the size of a plate. Season on both sides.