Prepare the Dressing: In a large mixing bowl, combine the mayonnaise, sour cream (or Greek yogurt), Dijon mustard, lemon juice, garlic powder, onion powder, and dried dill (if using). Mix until well combined.

Add the Chicken and Vegetables: Fold in the shredded or chopped chicken, chopped celery, red onion, and sweet pickle relish (if using) until everything is evenly coated with the dressing.

Season: Taste and season with salt and black pepper to your liking.

Chill: Cover the bowl with plastic wrap and refrigerate for at least 1 hour to allow the flavors to meld together.

Serve: Serve the chicken salad on a bed of lettuce, in a sandwich, wrap, or with crackers. Garnish with fresh parsley or chives if desired.

Enjoy your delicious Deli-Style Chicken Salad!