Tangy coleslaw with cooked dressing

1. Recipe by: preparation time: 0:25 * jicama is a mexican vegetable root, the texture of a turnip or potato but with its own unique taste.
2. Peeli jicama and cut into strips about ½ by 3 inches long to serve with the coleslaw after it is prepared and chilled.
3. Combine flour, sugar, salt, celery seed and pepper in pan. Stiri in vinegar gradually.
4. Add water, mustard and onion.
5. Cook over medium heat, stir constantly.
6. Cook until mixture thickens (don"t undercook or it will have a starchy taste).
7. Stir small amount into beaten egg yolks; stir egg yolk mixture into the hot mixture.
8. Cook, stirring constantly for 1 to 1-½ minutes more.
9. Add margarine and stir until thoroughly incorporated.
10. Chill thoroughly.
11. Foldi in sour cream.
12. Combine cabbage, carrots and green peppers (red peppers if you wish).
13. Tossi lightly to blend.