Cook the chicken. If you are starting with raw chicken, cook it in a skillet over medium heat until the thickest part reaches 165°F (74°C).
Let the chicken cool. Transfer the cooked chicken to a plate and let it rest for a few minutes. Cooling the chicken before mixing keeps the dressing creamy.
Chop the chicken. Cut the chicken into small, bite-sized pieces. You can shred it instead if you prefer a softer chicken salad.
Prepare the pickles. Chop the dill pickles into small pieces. If they are very wet, give them a quick drain so they don't add too much liquid to the salad.
Chop the vegetables. Finely chop the celery and red onion. Fresh, small pieces mix better throughout the chicken salad.
Make the dressing. Add the mayonnaise, pickle juice, Dijon mustard, black pepper, and garlic powder to a small bowl. Stir until smooth.
Combine the ingredients. Place the chicken, chopped pickles, celery, red onion, and fresh dill in a large bowl.
Add the dressing. Pour the dressing over the chicken mixture. Start with most of it and add more if you want the salad extra creamy.
Mix gently. Stir everything together until the chicken and vegetables are evenly coated. Don't mix too aggressively because you want the pickle pieces to keep some of their crunch.
Taste the salad. Try a spoonful and adjust it to your liking. Add a little more pickle juice if you want a stronger tangy flavor or a few more chopped pickles for extra crunch.
Chill before serving. Cover the bowl and refrigerate for at least 30 minutes. The short chilling time allows the pickle flavor to spread throughout the creamy dressing.
Serve. Spoon the chicken salad onto bread, crackers, lettuce, or a croissant. Add a small pickle spear on the side if you want even more pickle flavor.