STEP 1 Rub the garlic over the steaks then put in a sandwich bag and tip in the olive oil, sherry vinegar and parsley stalks. Smoosh everything together, then use a rolling pin to bash the steaks a few times. Leave for 1-2 hours. STEP 2 To make the sauce, put all the ingredients into a blender with 1 tbsp water and whizz until as smooth as possible. This will make more than you’ll need for the recipe but will keep for a week in an airtight jar. STEP 3 Heat a griddle or frying pan to high. Brush away the garlic and parsley stalks from the steaks and season well. Sear the steaks for 2 minutes on each side then rest on a plate. Put the ciabatta halves onto the plate, toasted-side down, to soak up any juices. STEP 4 Slice the steaks then stuff into the rolls with the green sauce and rocket.