For the celery salad, start with the celery stalks. Trim the leaves and keep aside. Now thinly slice the stalks on a deep diagonal. Place the celery stalk pieces in cold water for an hour. This will help soften them.
Meanwhile, prepare the other ingredients. Preheat the oven to 350 degrees Fahrenheit. Spread out the walnuts on a rimmed baking sheet and toast until brown. This should take 8-10 minutes.
Slice the apples with peels on. Quarter and then core the apple. Now cut each quarter in three. You should have 12 slices in all.
To make the dressing, put all the ingredients in a bowl and give them a brisk stir so that you have an emulsion.
To assemble the salad, pat dry the celery pieces. Put all the salad ingredients on a shallow plate and toss it to coat with the dressing.