Place chicken breasts in a sauce pot; add chicken broth and water to cover. Cover and bring to a low simmer over medium heat. Reduce heat to medium-low, and simmer, 15 minutes or until chicken is fully cooked. Remove chicken; let stand 20 minutes or until cooled; shred or chop and set aside.

Grate one teaspoon of zest from lemon; squeeze lemon into a large mixing bowl. Add lemon zest, mayonnaise, mustard, paprika, celery salt, pepper, and hot sauce; whisk vigorously until well blended. Add red onion, bell pepper, celery, garlic, capers and green onions; toss well.  Fold in chicken. Add additional mayonnaise, if needed. Cover and chill overnight.