Poppy Seed Dressing II

1 1/2 c. sugar 

2 T. dry mustard 

2 T. salt 

2/3 c. vinegar 

2 c. vegetable oil 

3 T. poppy seeds 

Prepare onion juice first by peeling, quartering, and puréeing a white onion in a blender. Strain off juice and discard residue. Mix sugar, mustard, salt, vinegar, and onion juice in the blender. On medium speed, add oil very slowly. Blend until thick. Add poppy seeds and blend again. Store in refrigerator.