Chicken Taco Soup

1½ lb. chicken breast 
6 Tbsp. chili powder 
3 Tbsp. ground cumin 
1½ tsp. garlic powder 
1½ tsp. onion powder 
½ tsp. sea salt 
4½ tsp. smoked paprika 
3 tsp. ground coriander 
1½ tsp. cayenne pepper 
32 oz. low-sodium chicken broth or stock 
1 (2.87 oz.) container chili powder 
2 qt. tomato juice
1 (15 oz.) can tomato sauce
2 (14.5 oz.) cans diced tomatoes
2 (15 oz.) cans black beans, drained
Fresh tomatoes, diced
Green onion, sliced
Lettuce, shredded
Black olives, sliced
Shredded cheddar cheese
Guacamole or diced avocado
Sour cream
Tortilla chips or thin tortilla strips

Combine the 6 tablespoons of chili powder, cumin, garlic powder, onion powder, salt, paprika, coriander, and cayenne pepper in a bowl; divide the mixture into a ⅓ portion and a ⅔ portion, set aside. 
Place the chicken breast pieces in a large stockpot. Mix the ⅓ portion of seasoning mix with a small amount of the chicken broth, stirring well, and pour over the chicken. Pour the remaining chicken broth over the chicken, cover the stockpot with a lid, and simmer until chicken is cooked through. When the chicken is completely cooked, remove from the stockpot and cool until you can handle it easily; shred the chicken with your hands into small bite-size pieces and return to the stockpot.
Mix the remaining ⅔ portion of spice mixture and the chili powder with some tomato juice and whisk until well incorporated, and then add it to the stockpot. Add the remaining tomato juice, tomato sauce, canned diced tomatoes, and black beans. Simmer the soup for at least an hour to allow all of the flavors to marry and enhance.
When soup is ready, serve it in bowls (make sure to leave some room at the top of your bowl) and top with fresh tomatoes, green onions, lettuce, black olives, shredded cheddar cheese, avocado, and sour cream. Sprinkle with thin-cut tortilla strips or serve with tortilla chips.