Prep the chicken. Use leftover roasted chicken, poached chicken, or a rotisserie chicken.
Chop or shred into bite-size pieces so it mixes evenly with the dressing.
Make the dressing. In a large bowl, whisk the Greek yogurt, Dijon, lemon juice, lemon zest, honey, garlic, salt, and pepper until smooth. Adjust the thickness with a splash of water if it feels too stiff.
Taste and tweak. Add a pinch more salt, lemon, or honey as needed. The dressing should be tangy with a gentle sweetness to balance it out.
Add the mix-ins. Fold in the celery, grapes or apple, red onion, herbs, and nuts.
Keep a few nuts aside to sprinkle on top for extra crunch.
Combine with chicken. Add the chicken to the bowl and stir until everything is well coated. Be gentle to keep the fruit and nuts from breaking down.
Chill for 20–30 minutes. Resting in the fridge helps the flavors come together and the dressing cling to the chicken.
Serve your way. Spoon into lettuce cups, pile on whole-grain bread, roll into a wrap, serve over mixed greens, or scoop with crackers and sliced cucumbers.