- 1 whole cauliflower
- 3 tablespoons + 1 teaspoon [50 g] butter
- 1 onion, chopped
- 3 medium potatoes, peeled then diced
- Salt and pepper, to taste
- 1 egg yolk
- 1/4 cup + 1 tablespoon [75 g] grated Emmental or Gruyere cheese
- Cut cauliflower into flowerets and chop cauliflower stems; blanch into salted boiling water for 10 minutes.
- Drain reserving cooking water separately.
- Melt butter into a large casserole; soften chopped onion without coloring.
- Add drained cauliflower pieces then pour in 1 or 2 ladles reserved cooking water.
- Add potato dices then pour in enough of remaining cooking water to completely cover the vegetables.
- Bring to a boil and leave to simmer for approximately 30 minutes, until really soft.
- Puree mixture into a blender; pour into a clean casserole.
- Reheat soup.
- If too thick, stir in more of remaining cooking water, until of desired consistency.
- Salt and pepper soup.
- Into a bowl, beat together egg yolk and grated Emmental or Gruyere cheese stirring in a little of the hot soup.
- Pour into hot soup stirring until well blended before serving.