Peel and chop the onion. Peel apples, up to 1/2, and remove core. Peel and wash the celery. Put aside about 50 g celery. Cut apples and remaining celery into small pieces.
Melt the fat. Fry apples, celery pieces and onion in it. Add vegetable stock and bay leaf. Season with salt and pepper and let it boil for about 20 minutes. Cut celery aside into wafer-thin slices.
Fry in hot oil for 2-3 minutes until golden brown. Take out, salt and let it drip off on kitchen paper. Heat olive oil in a small, coated pan. Leave the bacon in it until crispy. Cut the core out of the remaining 1/2 apple, cut apple into cubes.
Add the diced apples to the bacon and fry until transparent. Remove laurel from the soup, puree soup. Stir in 100 g whipped cream and horseradish, season to taste again. Arrange soup in bowls. Add 1 teaspoonful of cream to each bowl and mix until smooth.
Sprinkle with celery chips, apple and bacon cubes. Crusty bread tastes good with it.