Combine the following in a blender:
3/4 C sugar
1 t salt
1 t dry mustard
1-1/2 T onion juice or grated onion
1/3 C vinegar
Gradually add 1 C salad oil (not olive) and beat or blend until thick. Mix in 1-1/2 T poppy seeds.
Store covered in a cool place — may separate in fridge.