Rinse the celery root and greens, chop fine and pour with the oil, vinegar and mustard mixture. Keep for 1 hour.

Shred the ham, mushrooms, peeled and cored apple. Combine, season to taste with salt and toss in the mayonnaise.

Combine the salad with the prepared celery and put in a salad bowl. Garnish with potato and beet slices and greens.