Pour the salad leaves onto a large serving platter. Top with the kidney beans, feta and avocado. Squeeze some lemon juice onto the avocado to prevent it from turning brown. Fold the ribbons of cucumber into a concertina (accordion) shape and tuck in amongst the other salad ingredients.
Mix together the balsamic vinegar, olive oil, honey and some salt and pepper in a bowl and drizzle over the salad just before serving.