Preheat a grill (broiler) or barbecue grill to very hot. Put a couple of slices of lemon inside each sardine and season both sides with sea salt and some black pepper. Drizzle with half the olive oil.
Put the sardines on a tray and grill (broil) for 3 minutes on each side, or place the fish directly onto the barbecue. Check to see if the fish i