This old chestnut has lost popularity, but it really is a great salad when you make it with good ingredients. There's a really good write-up on it and its history at the Dutch foodie site Coquinaria.
Yield
4 Servings
Preparation time
10 minutes
Ingredients
1Celeriac (aka Celery Root)
2Apples (I like Northern Spy)
1⁄2 cMayonnaise
1⁄2 cWalnut Halves (toasted)
Instructions
Peel and dice the celeriac and the apples.
Add the mayonnaise and chill until ready to serve.
Stir in half the walnuts, and use the remainder for garnish.
Season with salt and a squeeze of lemon juice if it is not tart enough.
Notes
This came from the famous "Oscar of the Ritz", Maitre d'Hotel Oscar Tschirky.
Some recipes use green celery, but the celery root is all white, so the whole salad is white but for the walnuts, which can be a dramatic presentation.