1. Combine first 10 ingredients in a small saucepan over medium heat. Bring to a simmer; cook 3 minutes or until slightly thick, stirring occasionally. Add chicken to ketchup mixture; stir to combine. Cook 2 minutes or until chicken is thoroughly heated.
2. Spoon 3 tablespoons chicken mixture on bottom half of each bun; top each with 1 pickle chip and top half of bun.
For a less sweet option, use sliced dill pickles.