How to cook
Finely chop the leeks, garlic and celery stalks. You can grind them in a blender. Cut the meat and mushrooms into small cubes.
Heat the oil with one or two spoons of duck fat over medium heat and fry the vegetables. Stir well, because leeks burn easily.
After about 3-4 minutes, add the meat with a pinch of salt, the mushrooms and the remaining lard and fry them along with everything else.
Pour 6 cups (1.2 liters) of water and let the soup simmer, over medium heat, until the meat cooks and becomes tender.
Add the noodles, a little more salt, if necessary and continue boiling for as long as the noodles need to soften - 3-4 minutes or according to the instructions on the package.
Remove it from the heat and add water to the desired density without diluting it too much. This way, the temperature of the soup will drop directly and you will be able to thicken it immediately without waiting for it to cool down.
For the thickener, beat the egg with the yoghurt and a little salt. Temper with a few scoops of warm broth and pour everything back into the soup in a thin stream.
Stir and distribute the soup into bowls. Sprinkle each serving with freshly chopped parsley and ground black pepper.
Serve the delicious duck soup hot. It is good to consume it in that moment, because if it overheats, there is a risk that the egg from the thickener will lump up. This can only be avoided if you use two egg yolks instead of a whole egg.
Enjoy your meal!