Waldorf Salad

For 4 servings, prepare 2 apples, 2 celery stalks, 60 g walnuts, 4 teaspoons mayonnaise, 1 teaspoon lemon juice, 0.5 teaspoon sugar, and 100 g grapes. Rinse and dry the apples, then cut them into even bite-size cubes. Toss the cut surfaces immediately with the lemon juice so they remain bright while the other ingredients are prepared. Trim the celery, remove any noticeable tough strings, and slice it thinly. Halve the grapes and remove any seeds. Break only the largest walnut pieces so the finished salad retains their texture. Warm the walnuts in a dry pan over low heat for about 2 minutes, stopping when they smell fragrant, then let them cool completely before mixing. Stir the mayonnaise and sugar together in a large bowl until the sugar is evenly dispersed. Add any lemon juice left with the apples and mix until the dressing looks smooth. Add the apples, celery, grapes, and cooled walnuts. Fold from the bottom upward with a spatula and avoid pressing the fruit, which would release juice and thin the dressing. Cover the bowl and chill for 30 minutes. Stir once just before serving and check that the dressing still coats the ingredients lightly without pooling at the bottom.