Onion Salad Dressing 5 Ingredients: 2 cups of salad oil. 2 cups of white sugar. 2 teaspoons of salt. 2 teaspoons of dry mustard. 1 small onion. 1 cup of white vinegar. 2 teaspoons of celery seed. Directions: Combine first five ingredients in blender on high speed. Add vinegar slowly. Blend until thick. Add celery seed last. Download This Recipe