HEAT oven to 375ºF.
COOK and stir chicken and cumin in nonstick skillet sprayed with cooking spray on medium heat 2 min. Add peppers; cook 2 min., stirring occasionally. Stir in salsa; cook 2 min. Add Neufchatel; cook 2 min. or until melted. Stir in beans and tomatoes. (If using leftover chicken, cook the peppers and then stir in the chicken and cumin until warm)
SPOON 1/3 of chicken mixture into 8-inch square baking dish; cover with 1 tortilla and half each of the remaining chicken mixture and shredded cheese. Top with remaining tortilla and chicken mixture; cover.
BAKE 20 min. or until heated through. Sprinkle with remaining shredded cheese; bake, uncovered, 5 min. or until melted.