Cut the apples into quarters, remove the cores and cut them into pieces 1/2″ (1 cm) thick. Put them in a bowl, season with lemon juice.
Add the walnuts and celery. Drain the tuna and then tear it to pieces. Add to the salad. Mix the mayonnaise, cream and spices in a separate bowl and then add them.
Add lettuce and if desired, decorate with celery leaves. Serve immediately or chill in the refrigerator.