Combine cabbage and carrots and toss to mix.
Whisk egg yolks in a small bowl until light lemon color. Add sugar, mustard, Tabasco. Continue whisking until well combined.Melt butter in a medium size pan and whisk in flour beating constantly for approximately 2 minutes.
Stirring constantly, add yolk mixture to butter and flour mixture and cook, over low heat, until it thickens. Be sure mixture does not boil.Remove from fire and cool. Combine sour cream and correct seasoning. Cover and refrigerate until serving.Before serving toss half of dressing to coat cabbage and carrots. If necessary add more dressing.Serve.