1 sm. onion
3/4 c. sugar
1 tsp. celery seed
1 tsp. salt
1/3 c. vinegar
1/2 tsp. pepper
2 tbsp. prepared mustard & 1 tbsp. Dijon mustard or horseradish mustard or 3 tbsp. prepared mustard (a total of 3 tbsp. mustard)
1 c. cooking oil (not Mazola)

Put all ingredients in blender and mix well. Chill. Good on all kinds of salads and slaw. Keeps for a month in refrigerator.