Combine all the Greek salad ingredients and season with pepper. Set aside while you cook the sardines.
Brush the sardines with a little of the oil and season well with salt and pepper. Place the fish on a hot barbecue and cook for 3–4 minutes on each side, or until the fish is firm to the touch.
Drizzle the slices of ciabatta with the remaining oil and place on the barbecue to toast. When they are toasted, rub both sides with the garlic clove.
Top the ciabatta with the Greek salad and serve with the warm barbecued sardines.