If you don't have cooked chicken, roast or poach approximately 7–8 lb raw bone-in chicken breasts/thighs to yield 6 lb cooked meat. Cool slightly, remove skin and bones, then dice or shred into bite-sized pieces. Spread the diced/shredded chicken in a large mixing bowl or directly into a clean 9x13 pan if you prefer to mix in pan.

Chop vegetables and mix wet ingredients

Finely dice the celery and red onion; halve grapes if using. In a separate medium bowl, whisk together the mayonnaise, Greek yogurt, Dijon mustard, lemon juice, and sugar (if using) until smooth.

Add the diced celery, minced red onion, relish (or diced pickles), chopped parsley and halved grapes to the bowl or pan with the chicken.

Pour the mayonnaise-yogurt mixture over the chicken and vegetables. Using a large spatula or spoon, fold the dressing into the chicken gently until evenly coated. Avoid over-mashing the chicken—mix until ingredients are uniformly distributed.

Seasonings & Add-ins

Sprinkle the kosher salt, black pepper, celery seed, smoked paprika (if using) over the salad. Fold gently to incorporate and taste. Adjust seasoning—add up to 1 tsp more salt or pepper as needed, and more lemon juice for brightness.

Chill the assembled chicken salad in the refrigerator for at least 1 hour (preferably 2–4 hours) to allow flavors to meld. For best texture when serving a full pan for an event, prepare no more than 24 hours ahead.

Assembly & Garnish

If you mixed in a bowl, transfer the chilled chicken salad into a lightly oiled or lined 9x13 pan and spread it evenly. Smooth the top with an offset spatula.

Arrange lettuce leaves or mixed greens around the edges or on individual serving plates. Garnish the top of the pan with sliced tomatoes or cucumber and sprinkle chopped chives or extra parsley for color.

Serve chilled. Provide serving utensils and let guests scoop onto bread, croissants, crackers, or greens. Leftovers: cover tightly and refrigerate up to 3 days.