Total time: 30 min • Prep: 15 min • Cook: 15 min • Serves: 4 • Difficulty: Easy

This classic salad is the perfect side dish for picnics and barbecues because it goes well with any meat or fish. It was reportedly created by the maître d’hôtel of the Waldorf-Astoria Hotel in 1893 and contained just three ingredients: apples, celery, and mayonnaise. Later grapes and nuts were added, and it has been popular ever since. You can store any leftovers in a covered container in the refrigerator for up to two days. You don’t have to toast the walnuts, but doing so crisps them and brings out their flavor. The easiest way is to toast them in a skillet over medium heat, tossing occasionally, until their edges turn brown. Transfer the nuts to a plate and let cool.