For the celery cordon bleu, cook the celery slices in lemon water until al dente (about 10 minutes) and drain.
Top celery slices with ham and cheese and cover each with a second celery slice, season with salt and pepper.
Dredge the slices in flour, beaten egg and breadcrumbs and fry in fat until light brown. Garnish the celery cordon bleu with lettuce and lemon slices.