I like to pull the chicken while it's still a little warm since the meat comes off the bone so much easier that way. Remove the skin and bones, then shred or dice the meat into bite-sized pieces. Try to keep the pieces fairly even so every bite has the same texture.
While the chicken cools slightly, I dice up the celery, red onion, and grapes on my cutting board. Keeping everything a similar small size helps the salad hold together better and makes it easier to scoop. This is also when I toast my nuts in a dry skillet for a couple of minutes.
In a small bowl, I whisk together the mayonnaise, Greek yogurt, Dijon mustard, and lemon juice until it's completely smooth. I always taste it at this stage and adjust the salt and pepper before it goes anywhere near the chicken. A smooth, well-seasoned dressing makes or breaks this recipe.
Now I add the shredded chicken, celery, onion, grapes, and toasted nuts into my large mixing bowl. I pour the dressing over the top and use a rubber spatula to gently fold it all together. I try not to overmix so the chicken doesn't turn mushy and the grapes stay intact.
I always pop the bowl in the fridge for at least 30 minutes before serving, covered with plastic wrap or a lid. This resting time lets the flavors really meld together and the salad firms up slightly, making it much easier to scoop onto bread or crackers.