Tangy fish salad

Ingredients

• 455g smoked fish fillets, fresh or defrosted, skinned and cubed ( a smoked blue-eye travella or even fresh non-smoked Pink Ling Fish works is great in this recipe)
• 150ml water
• Grated rind of half a lemon
• 2 sticks celery, sliced
• 1 red apple, cored and sliced
• 30g walnuts or mixed nuts, halved
• Salt and black pepper
• 150ml natural yoghurt or fromage frais
• Mixed lettuce leaves, to garnish