1 beaten egg
Scant 1/2 c. sugar
1 tbsp. flour
1/2 c. water
1/2 c. cider vinegar
2 tbsp. butter
1 tsp. salt
1/4 tsp. pepper

Combine in a saucepan in given order, stirring with each addition. Boil gently until thickened. Cool. Put onto potatoes, eggs, celery, etc. Mix.