Cook the chicken: Bake seasoned chicken breasts at 375F for 18 to 20 minutes, or use white meat from a store-bought rotisserie chicken for a faster option.
Cool completely: Let the cooked chicken rest to room temperature, then refrigerate for 15 minutes before dicing to prevent the mayo from thinning.
Dice the chicken: Cut the fully cooled chicken into even ½-inch cubes using a sharp knife. Consistent size ensures every bite has the same satisfying texture.
Prepare the celery: Remove strings from each celery stalk by snapping and pulling. Slice thin on a diagonal, about ⅛-inch thick.
Combine and season: Add diced chicken and sliced celery to a large bowl. Sprinkle the black pepper over the mixture and toss gently to distribute evenly.
Fold in the mayo: Spoon Duke’s mayo over the chicken mixture. Using a large spatula, fold with slow, wide sweeps until just coated. Do not overmix.
Taste and adjust: Taste the salad and add a pinch more black pepper if desired before chilling.
Chill before serving: Cover the bowl and refrigerate for at least 30 minutes. Serve on a sub roll, over lettuce, or with crackers.
