Nancy, a longtime family friend, shared the dressing recipe, reporting that it came from "Lancaster Entertains", a cookbook published by the Lancaster Medical Society Auxiliary--at least 50 years ago! It is credited to Evelyn Jones, a friend of Nancy's mother.
Nancy keeps a jar in her fridge, using it as her go-to salad dressing. I found it well suited for a basic spinach and strawberry salad and a perfect match for my friend Daina's favorite salad combination that follows.
FOR THE DRESSING
3/4 cup sugar
1/3 cup vinegar (I used apple cider vinegar; plain white vinegar may be used)
1 teaspoon salt
1 teaspoon dry mustard
1 teaspoon celery seed
1/4 cup chopped onion
1 cup salad oil
Fresh or dried blueberries
Goat cheese (could substitute feta or another cheese of choice)
Optional extras: sliced radishes, slivered red onion, sunflower seeds, slivered almonds or other nuts of choice
Mix all the dressing ingredients in blender for a minute or two and store in the refrigerator.
Top a bed of your favorite greens with blueberries, avocado, almonds, and goat cheese. No need to be precise in the measurements. Simply add according to preference.
Drizzle with the dressing, toss, and enjoy!
I found that blending for a minute or two was enough time to sufficiently mix. I also mixed a batch with a whisk after mincing the onions very finely. This is a fine option if you do not have a blender.