1 tbsp. butter
1 tbsp. chopped shallots or white part of scallion
Pinch of cayenne
1 c. heavy cream
1/4 c. dry sherry or Special Madeira wine
3 med. size egg yolks
Tiny pinch of grated nutmeg
Salt & ground white pepper

In the top pan of a double boiler melt the butter and soften the shallots or scallion. Add the cayenne and 3/4 of the cream and heat through; leave over simmering water for 5 minutes to reduce slightly. Add the sherry or Madeira.

Beat the yolks with the remaining cream. Stir in a little hot sauce and return to the pan. Cook, stirring, until thickened. Season to taste with nutmeg, salt and pepper.

Up to 1 cup sliced, sauteed mushrooms can be added to bulk the sauce out if it is to be used as a filling (not traditional). Reserve a little plain sauce for dribbling over crepes.