3 sticks celery; 2 sweet apple; 6 tbsp mayonnaise; 1 tbsp lemon juice; a handful of walnuts; salt, black pepper
Roast the nuts in a frying pan and then crush them with a pestle and mortar or in a blender. Remove the strings from the celery and dice it into small cubes. Remove the cores from the apples and dice them into small chunks. Squeeze the lemon juice over the apples straight away and stir it through to stop them from browning. Mix everything together with the mayonnaise and nuts, season to taste. Serve the Waldorf on lettuce leaves.