Ingredients

• 2 level tablespoons tarragon, freshly chopped (or 1 tablespoon dried tarragon)
• 2 shallots or 1 small onion, peeled and very finely chopped
• 1 tablespoon wine vinegar
• 100 g/4 oz cup mushrooms, trimmed and finely chopped
• 120 ml/4 fl oz dry sherry
• 120 ml/4 fl oz single cream
• 50 g/2 oz butter
•   salt and freshly ground black pepper

Method

1. Put the tarragon, shallots or onion and vinegar into a small saucepan and simmer gently until reduced by half.
2. Add the mushrooms and sherry, bring to the boil and simmer gently for 5 minutes.
3. Carefully blend in the cream and butter and bring very slowly back to just below boiling point, stirring continuously until the butter has melted.
4. Season with salt and freshly ground black pepper. Serve hot.

Notes