Allow toasted nuts to cool completely before mixing them into the salad so their heat does not affect the yogurt-based dressing.

Use a tart, crisp apple such as Granny Smith for the best crunch and flavor.

The salad is best freshly prepared. Refrigerate leftovers in an airtight container for 2 to 3 days.

For advance preparation, prepare the grapes, celery, parsley, toasted nuts, and dressing up to one day ahead and refrigerate them separately. Wait to cut the apples to minimize browning.

You can assemble the full salad about 2 to 3 hours before serving, but making it much earlier can reduce its ideal texture.

You can use all Greek yogurt instead of mayonnaise if desired.

Red or green apples work, although tart green apples provide extra crispness.

Red or green grapes both work well.

You can replace walnuts with pecans, almonds, or pistachios.

Optional additions include dried cranberries, raisins, chopped apricots, or dates.

You can replace the grapes with diced pears.

For a more substantial meal, add cooked chicken or turkey.

Serve the salad alone or over romaine, Bibb, butter lettuce, or other crisp lettuce leaves.