Juice the lemon and mix with the olive oil, salt and pepper to make your vinaigrette.
Wash the romaine lettuce, drain well and then thinly slice. Wash the cucumber and the tomatoes. Cut the cucumber into slices and cut the tomatoes into wedges, removing the tough base of the stalk. Peel and finely dice the onion. Cut the feta in cubes.
Place the chopped ingredients in a bowl and add the olives. Pour the vinaigrette over the salad and toss it gently to dress thoroughly..
«You can make the salad in advance but do not add the dressing until you are ready to serve, this will keep the salad leaves fresh.»