PREHEAT oven to 400°F Mix 1/2 cup of the shredded cheese, the Neufchatel cheese, green peppers, oregano and garlic salt until well blended. Shape into 4 logs. Place 1 log on one of the short ends of each chicken breast; press into chicken lightly. Roll up each chicken breast tightly, tucking in ends of chicken around filling to completely enclose filling.
PLACE, seam-sides down, in 13x9-inch baking dish sprayed with cooking spray. Spoon spaghetti sauce evenly over chicken; cover with foil.
BAKE 30 minute or until chicken is cooked through (170°F). Remove foil; sprinkle chicken with remaining 1/2 cup shredded cheese. Bake an additional 3 to 5 minute or until cheese is melted.