Festive Meat and Veggie Soup
Heat 2 tbsp butter in a pan and sweat the diced ingredients for a few minutes. Sprinkle with chopped parsley leaves.
Add the water and the bread drink, season with salt and bring to the boil. Simmer for 20 minutes.
Heat the rest of the butter in a pan until it foams, stir in the flour and sweat without browning. Take about 2 ladlefuls of the soup, stir it into the roux and then stir the roux into the soup.
Bring to the boil, cook until it thickens slightly and season with salt and pepper.
Mix the sour cream with the egg yolk. Remove the soup from the heat and carefully stir in the sour cream and egg yolk mixture. Add lemon juice to taste (it should be sourish).