Ingredients

• 4 oz. butter
• 1 level tablespoonful plain flour
• ¼ pint light stock, chicken or veal, or liquid from cooked vegetables
• 1 level teaspoonful parsley, chopped
• 1 teaspoonful lemon juice
• 1 egg yolk
• 1 tablespoonful single cream
•   salt
•   white pepper, freshly ground
• a pinch savory, chopped (optional)

Method

1. Melt the butter in a pan, take it off the heat and stir in the flour. Cook this mixture over a gentle heat, stirring all the time, until it is a pale straw colour.
2. Remove from the heat and whisk in the stock. Continue whisking the sauce over a gentle heat until it comes to the boil, then simmer for a few seconds.
3. Beat in the chopped parsley and lemon juice.
4. Beat the egg yolk and cream together. Add two tablespoonfuls of the hot sauce and stir them together.
5. Pour the rest of the sauce into the basin, return the sauce to the pan and stir it over a gentle heat until it thickens a little more. Be very careful not to boil the sauce at this stage or it will curdle.
6. Season carefully and add the chopped savory if available.

Notes