Blanch the tomatoes and cut them into large chunks.
Wash the nectarines and the cucumber and dice them.
Chop the feta into cubes and keep it cold.
Mix the tomatoes and the nectarines with the lemon olive oil and a few fresh basil leaves.
Peel long slices of cucumber with a vegetable peeler.
Line circular presentation rings with the cucumber slices and build the salad. Arrange the diced feta harmoniously round the circles and decorate with a basil leaf and the slivers of red onion.
Serve well chilled.