Velvety Celery Cream Soup

Preparation

• 1
  Peel the celeriac and cut into cubes of approx. 2 cm. Finely dice the onion. Peel the potatoes and cut into cubes of approx. 1 cm.
• 2
  Thoroughly wash the organic lemon. Carefully peel off a few strips of the yellow zest with a vegetable peeler (only the yellow, not the bitter white). Halve the lemon and squeeze the juice from one half.
• 3
  Melt the butter in a pot over medium heat. Sauté the celeriac and onions for 3–4 minutes, stirring occasionally. Add 200 ml of the whipping cream and the lemon zest, and bring to a brief boil.
• 4
  Add the broth (or stock), potato cubes, vinegar, lemon juice, sugar, one teaspoon of salt, and a pinch of pepper. Bring everything to a boil again, reduce the heat, and simmer for approx. 20 minutes until the vegetables are soft.
• 5
  Remove the pot from the heat and remove the lemon zest. Finely blend the soup with an immersion blender. Then return it to the stove and bring to a brief boil again.
• 6
  In a small bowl, whisk the remaining cream (100 ml) with the egg yolks. Finally, remove the pot from the heat and stir the egg yolk-cream mixture into the soup (to thicken). Season with salt to taste. The soup must not boil from now on, otherwise the egg yolk will curdle.