In a small bowl, combine garlic powder, cayenne pepper, brown sugar, chili powder, smoked paprika, salt, ground coriander, and ground cumin. Mix well until evenly combined.

In a large mixing bowl, toss the shredded cooked chicken with dill pickle juice and the prepared spice mix.

Dice the onion and celery, and rinse and drain any canned beans.

In a Dutch oven, heat a tablespoon of butter over medium-high heat. Add the diced onion and celery, sautéing them for about 5 minutes until they turn translucent.

Stir in the marinated chicken, chicken broth, rinsed beans, and canned diced tomatoes.

Bring the mixture to a rolling boil, then reduce heat to low and cover. Allow it to simmer gently for 30 minutes.

After simmering, ladle the chili into bowls and serve hot with sliced dill pickles and a dollop of Greek yogurt.