##celery## peel and halve. Cut off 4 wafer-thin slices, dice the rest roughly. ##Peel, wash and chop the potatoes##. ##Apple## quarter, remove seeds and dice finely.
Fry the ham in a pot until crisp and take it out. Heat the oil in the ham fat. Fry the celery slices in it until crispy and take them out. Set aside with 1 tsp. apple cubes. Put the celery and the rest of the apple cubes into the pot.
Add 300 ml water and milk and bring to the boil. Stir in stock. Cover and simmer for about 20 minutes.
Puree the soup. Stir in sour cream and horseradish. Cook the apple cubes in the soup for 3 minutes. Season to taste with salt, pepper and 1 pinch of sugar. Sprinkle with the crispy celery slices and ham.