This recipe makes a large amount, so may want to cut in half.

2		Eggs (beat in double boiler)(May use 3 egg yolks instead)
1/2	C	Sugar
2		Bouillon cubes in 1/2 cup hot water
1/2	C	French mustard
1/2	C	Vinegar
2	tbsp	Flour
1/4	C	Butter

Cook in double boiler until thick, beating occasionally. Serve cold.