300 g (3/4 lb) veal or pork bones, 100 g (4 oz) vegetables for soup (carrots, parsnips, kohlrabi), 150 g (6 oz) mushrooms, 50 g (2 oz) butter, 50 g (2 oz) flour, 60 g (5 tbs) single cream, 6 tbs milk, 1 egg yolk, salt, 1 tsp noble sweet paprika, freshly ground pepper, 1 roll for making croutons.
Make a stock with the bones and remove any fat. Wash and chop the mushrooms. Heat the butter in a large pan and fry the mushrooms. Season with the paprika and add salt and pepper to taste. Sprinkle with flour, pour in the stock and bring to the boil, stirring until thick. Add the milk, then strain. Blend the egg yolk and cream together and add to the strained soup. Bring to the boil and serve with croutons made from the roll which has been toasted and cut into small pieces.