Put the raw white haricot beans in 2 liters of cold water for 8 hrs. Put the haricot beans into the pot, cover with 1 liter of cold water, and cook through (approximately 60 mins). Add some water if necessary. Cool the haricot beans.
Cook the liver in salted water until ready. The chicken liver is cooked in 15-20 minutes, the beef liver in 30 minutes. Don’t overcook the liver because it will be stiff. Cool and shred the liver.
Rinse pickled mushrooms in cold water. Cut them into pieces.
Dice the onion, slightly brown it in the vegetable oil.
Coarsely grate the carrot, add it to the frying pan; cook it until soft. Cool the carrot.
Combine all the ingredients, add the salt, pepper, and stir through the mayonnaise. For low-fat variant use the sour cream instead.