Peel and chop the onions. Potatoes peel, wash and in rough cubes cut. Heat 1/2 tsp. oil in a pot. Fry the onions for about 3 minutes. Add potatoes and fry briefly. Deglaze with broth, bring to the boil and simmer for about 20 minutes
Meanwhile, wash the chanterelles and lamb's lettuce, clean them thoroughly and drain them well. Wash the fish, dab dry and cut into 3 pieces of about the same size. Remove the core from the apple. Cut apple into 3 pieces of about the same size. Put pike-perch and apple alternately on a skewer. Season with salt and pepper
Add 100 g lamb's lettuce and cream to the soup and simmer for about 2 minutes. Puree the soup with a hand blender, season to taste with salt, pepper and nutmeg. Keep soup warm
Heat 1/2 tsp. oil in a frying pan. Fry the fish for about 5 minutes on the skin side. 2-3 minutes before the end of the cooking time add chanterelles and fry while turning. Add 25 g lamb's lettuce to the chanterelles and allow to collapse. Season to taste with salt and pepper. Arrange lamb's lettuce soup, chanterelles and pike-perch skewer