Cut the carrot and leek into very fine, 3 - 4 cm long julienne, put a few strips aside. Put the meat stock and wine in a saucepan, heat and add the vegetables, the diced porcini mushrooms and half of the finely chopped onion. Let simmer for about 10 minutes.
Drain the snails and chop finely. Add the snail stock to the vegetables. Sweat the sliced snails with the second finely chopped onion half and the finely chopped garlic in butter.
Add everything to the broth and simmer for another 10 minutes over low heat. The vegetables should be done. Season with basil, salt, pepper and nutmeg. Remove the pan from the heat, whisk the egg yolks with the créme fraiche and stir into the soup. Carefully heat up again slightly, but don`t let it boil anymore.
Pour into preheated soup bowls, sprinkle with the herbs and garnish with a few julienne. A glass of white burgundy and fresh baguette are enough.
Note: With a little more vegetables, porcini mushrooms and créme fraiche, but less broth, it becomes a filling main meal.
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