Carefully remove the two outer membranes from the fillet and either finely lard it with strips of salt pork fat or wrap in thin slices of salt pork fat. In certain cases the fillet may be wrapped around with very thin slices of flattened beef fat which are held in place with string.
It should be roasted at a high temperature allowing 12-15 minutes per 1 kg (2¼ lb) if roasting in the oven, keeping it pink and underdone in the middle; for spit roasting allow 18 minutes per 1 kg (2¼ lb..