How to make
Peel and dice the carrots and potatoes and finely chop the leeks and garlic.
Clean the mushrooms from the soil, separate the stumps and peel off the caps, then you can rinse them quickly, so that they do not absorb water. Cut them into medium-sized pieces.
Heat the oil in a pot and fry the carrots first with a pinch of salt, then add the leeks, garlic, tomatoes and mushrooms at 3-4 minute intervals. After you add the last ones, add the butter, because the mushrooms will absorb a lot of the fat.
Cook for a few minutes, while stirring and pour about 6 cups (1.2 liters) of water and a cube of broth and thyme. For more flavor, you can add a spoonful of vegetable spice.
Once the soup boils, add the potatoes and boil for 20 minutes, then turn off the hob and leave it to cool - it should be hot, but not boiling. If the water has greatly reduced its level, top it up.
Beat the yolk with the yoghurt and two pinches of salt and pour two scoops of the soup broth over them, then pour the thickener in a thin stream to the broth and stir.
Serve the mushroom soup hot, sprinkled with chopped fresh parsley.
The Mushroom Soup with Leek and Potatoes is delicious and easy.