Cook eggs in a saucepan of boiling water until soft-centred (6 minutes). Drain and refresh in cold water; then peel and halve. Divide potato salad among bowls. Top with watercress, apple and egg.

An easy potato salad recipe that mixes mayonnaise with lemon juice to brighten it up. If you want to take it up a notch, stir in freshly chopped herbs and some capers or pickles (see recipe tip ...