Place chicken breast halves on a medium baking sheet. Bake in the preheated oven 20 minutes, or until no longer pink. Remove from heat, cool and shred.
Place shredded chicken in a medium bowl, and mix in cream cheese, mayonnaise,
Cheddar cheese, green chili peppers and jalapeno pepper. Transfer the chicken mixture to a medium baking dish.
Bake uncovered in the preheated oven 30 minutes, or until the edges are golden brown.