Prep the chicken. Drain canned chicken well and press out excess liquid. Use a fork to gently flake it into bite-size pieces.
Make the dressing. In a medium bowl, whisk together mayonnaise, Greek yogurt, Dijon, and lemon juice.
Add a pinch of salt and pepper.
Add the mix-ins. Stir in celery, red onion, grapes or apple (if using), and parsley. Sprinkle in nuts or other optional ingredients if you like.
Combine. Fold the chicken into the dressing until evenly coated. Taste and adjust with more lemon, salt, or pepper.
If you want extra tang, add a dash of Dijon.
Chill briefly. For best texture and flavor, refrigerate 15–30 minutes. This helps it set and meld.
Serve. Spoon onto bread with lettuce, tuck into a wrap, pile over greens, or serve with crackers and sliced veggies.