My mom claimed this dip came from her mother-in-law from the 1950's. I have my doubts about this provenance as I don't think my grandmother cooked anything. No one I know makes anything like it. Sweet and sour, it goes well with a salty dipper. —HenrysMom
Whisk sugar, vinegar and eggs until sugar is dissolved.
Over low heat, cook egg mixture in a small skillet. Cook gently, stirring constantly, until mixture thickens. (Eggs will not set into curds like scrambled eggs.) Alternatively, mixture can be cooked until thick in a double boiler.
Place cream cheese, grated onion, egg mixture and a pinch or 2 of salt in a blender. Process until smooth. Scrape into bowl, garnish with scallion tops or chives. Chill several hours before eating.