Combine in a medium bowl:
- 1 cup diced celery
- 1 cup diced cored and peeled apples
- ½ cup coarsely chopped toasted walnuts
- ½ cup halved seedless red grapes
Stir in:
- ⅓ to ½ cup mayonnaise or plain yogurt, to taste
- ¼ teaspoon salt
- ⅛ teaspoon black pepper
Serve at room temperature or chilled.