Sauce Matelote blanche (White Matelote Sauce)

Ingredients

• 3 décilitres white-wine fish court-bouillon
• 25 grammes mushroom peelings
• 8 décilitres Velouté de poisson
• 150 grammes butter
• 1 point cayenne
• 20 small onions glazed in butter
• 20 small mushroom caps

Instructions

1. Add 25 grammes of mushroom peelings to 3 décilitres of white-wine fish court-bouillon and reduce by two thirds.
2. Add 8 décilitres of Velouté de poisson and let it boil (the printed number of minutes is illegible in the source).
3. Finish with 150 grammes of butter and sharpen with a point of cayenne.
4. Pass through the étamine.
5. Add the garnish: 20 small onions glazed in butter and 20 small mushroom caps, cooked and very white.