Waldorf Salad

Serves 1   1 medium red apple, cored and diced 1 tbsp lemon juice, fresh or bottled 50g/2oz celery, diced 2 tbsp low-fat yogurt or fat free fromage frais Crisp lettuce leaves 4 walnut halves, crushed Toss the diced apple in lemon juice to prevent discoloration. Drain...