BLEND broth, barbecue sauce, crushed pepper and 3/4 cup nuts in blender until smooth.
HEAT 1 tsp. oil in large nonstick skillet on medium-high heat. Add chicken; cook 5 min. or until done, stirring occasionally. Remove from skillet; cover to keep warm.
ADD remaining oil to skillet. Add onions and bell peppers; cook and stir 5 min. or until crisp-tender. Meanwhile, cook spaghetti as directed on package, omitting salt.
DRAIN spaghetti. Add to ingredients in skillet along with the chicken. Remove from heat. Add peanut sauce; mix lightly. Sprinkle with cilantro. Serve topped with remaining nuts.