Make the dressing: In a large bowl, whisk together mayonnaise, Greek yogurt, smoked paprika, Dijon mustard, lemon juice, garlic, salt, and pepper until smooth and evenly colored.
Add the mix-ins: Stir in celery, red onion, and parsley.
If you like heat, add a small pinch of cayenne.
Fold in the chicken: Add the shredded or diced chicken and gently mix until everything is well coated. Taste and adjust salt, pepper, and lemon juice.
Chill for best flavor: Cover and refrigerate for at least 30 minutes so the flavors meld. The paprika deepens and the texture improves.
Serve: Spoon into lettuce cups, pile onto cucumber slices, wrap in a low-carb tortilla, or fill avocado halves.
Add extra herbs or a sprinkle of smoked paprika on top if you like.