1. Sprinkle salt over the onions and leave for about 5 min., then rinse the onions and press out as much liquid as possible.
2. Toast the bread and cut it into cubes for the croutons.
3. Toss the spinach with the oil and arrange on a platter with the cucumber, beans, onions and Fetta.
4. Sprinkle with mint, lemon zest, pepper and some of the croutons. Serve the salad with grilled chicken or salmon and the rest of the croutons.