Potage Germiny — Sorrel and Egg Yolk Soup

Ingredients

• 1.2 litres consommé or very clear, well-flavoured chicken broth, excellent quality; clarity is essential
• 200 g fresh sorrel, central stems removed, leaves cut into fine chiffonade
• 30 g unsalted butter
• For the liaison
• 6 egg yolks, whisked smooth with the cream
• 200 ml double cream, whisked smooth with the yolks

Method

1. 1
   Wash the sorrel thoroughly. Remove and discard the central stems. Stack the leaves and cut across into fine chiffonade — thin, even ribbons. Melt the butter in a wide pan over moderate heat and add the sorrel. Cook for 2–3 minutes, stirring. The leaves will collapse dramatically and shift from vivid green to olive-khaki as the oxalic acid reacts with heat; this colour change is correct and inevitable. The sorrel is ready when it has fully wilted and its volume has reduced to a fraction of the raw quantity.
2. 2
   Bring the consommé to a gentle simmer in a heavy pot. Add the wilted sorrel and its butter. Keep the broth hot but do not allow it to boil rapidly.
3. 3
   In a bowl, whisk together the 6 egg yolks and 200 ml of double cream until the mixture is completely smooth and homogenous — no streaks of yolk should remain. This is a particularly generous liaison; the finished soup will be almost custard-like in richness.
4. 4
   Temper the liaison: ladle a spoonful of the hot broth into the yolk-cream mixture, whisking constantly. Add a second ladleful, still whisking. The liaison is now warmed gradually and safe to introduce to the pot. Pour the tempered mixture back into the pot in a steady stream, stirring continuously with a wooden spoon. This step — the tempering — is where the dish lives or dies: the yolks must never meet the full heat of the soup without this gradual introduction, or they will scramble instantly and without remedy.
5. 5
   Set the pot over the lowest possible flame. Stir continuously with a wooden spoon, keeping the soup in constant, gentle motion. Heat until the soup thickens enough to coat the back of the spoon — the internal temperature must not exceed 82–84°C. At the first sign of graininess or curdling, remove the pot from the heat immediately and strain through a fine sieve into a cold bowl.
6. 6
   Serve at once in warm bowls. The finished Germiny should be pale gold with flecks of olive-green sorrel, with a texture silky as satin. It will not hold: the liaison continues to thicken on residual heat and cannot be reheated without curdling.