Remove most of the dark green from the leek stalks. Wash the leek and cut into thin rings and place in an appropriately sized bowl. Chop the hard-boiled eggs, add the celery salad and the chopped tart apples. Then stretch the mayonnaise with a little cream or condensed milk. Add salt, pepper, sugar and a little lemon juice and season to taste. Then mix the resulting dressing under the leek.