The key to this salad is to maintain crunchiness and not be watery, so it's best to assemble it close to serving and cut the apples at the last moment.
Toast ½ cup pecans or walnuts on a clean baking sheet in a low oven (about 300°F or 150°C) for about 10 minutes, stirring once or twice. The aroma will be nutty and warm. Let them cool completely, then chop finely.
For the dressing:
Mix 2 tablespoons mayonnaise, 2 tablespoons Greek yogurt, 2 tablespoons heavy cream, 1 tablespoon lemon juice, 2 teaspoons honey, ⅛ teaspoon salt and a large pinch of black pepper (or to taste) in a medium bowl until smooth. You can prepare it several hours ahead and store it in the fridge in an airtight jar. Stir before using.
Assembling the salad:
In a large bowl, combine ¾ cup chopped celery stalks1 cup seedless grapes, halved.
Wash and core 2 green apples, unpeeled, and cut them into small cubes. Add to the celery mixture.
Pour half of the dressing over the salad and gently toss together until evenly coated. Sprinkle the toasted nuts and add more dressing as needed. Taste and adjust seasonings before serving.
Notes
Adjust, adjust, adjust. I can't stress enough how important this is, as you'll be eating it. Want more sweetness? Add more honey. Not enough salt or lemon? Adjust until you find the right balance. Want more celery and fewer apples? Change the ratio. Make it your own.To avoid sogginess and browning, don’t prepare the full salad too far ahead. It’s best assembled shortly before serving, though a 15-minute chill is fine. You can prep the dressing, chop the celery, and toast the nuts in advance—store the first two in airtight containers in the fridge and the nuts in a sealed jar.Variations: add some raisins instead of grapes and use another type of apple. Red apples are sweeter than Granny Smith (green ones), so adjust the amount of honey in the dressing, unless you want a sweeter salad.