1beat egg, add sugar and flour stir until smooth.
Add vinegar.Mix well no lumps. Cook on low to med. heat on stove top whisking constantly. Cook until thick as mayo. Do not stop stirring as you don't want scrambled eggs.Take off burner and let cool completely. When dressing has cooled add mayo. Season to taste. I like my sauce speckled with celery salt. This takes about 12 minutes to thicken.
2Cop cabbage and celery by hand. Grate carrots. How much celery and carrots you need depends on the size of your cabbage. Add to make look good.
Chill well. The sauce will thin out as it sits.
yield 1 1/2 pounds. I always make this hours ahead or the night before.