333 Sprat sauce

• 1 spoon butter
• 1–2 onions
• 2–3 egg yolks</

Melt 1 spoon butter in a saucepan, add small cut-up sprats and finely chopped onions, and bring to a boil. Add cream and a little bouillon, bring to a boil again, and cool slightly. Beat in egg yolks and