Step 1

Place the chicken, dill pickle juice, and buttermilk in a zipper bag. Place the bag in the fridge, and let the chicken marinate for at least 30 minutes, but preferably for several hours.

Step 2

In a small bowl, combine the salt, ground black pepper, garlic powder, onion powder, and celery salt. Remove the chicken from the marinade and season on both sides with the seasoning blend.

Step 3

Heat the grill to 350°F or use a grill pan. Brush the grill with oil.

Step 4

Place the chicken on the grill. Cook for 3 to 4 minutes on each side until the chicken reaches an internal temperature of 165°F.

Step 5

Remove the chicken from the grill, let it cool, and chop it into 1-inch cubes.

Step 6

Place the chicken, celery, sweet pickle relish, mayonnaise, and hard-boiled eggs into a food processor. Pulse a few times until the chicken has a very fine texture. Season with salt and pepper.

Step 7

Lightly toast 2 slices of bread. To build the sandwich, place a few lettuce leaves on one slice of bread followed by a few tomato slices and some chicken salad. Place the other slice of bread on top.