COOK and stir onions, peppers and chiles in large skillet on medium-high heat 5 min. or until onions and peppers are tender.
FILL bolillos with turkey, vegetable mixture and Singles. Spread outside of bolillos with mayo.
COOK in skillet on medium heat 3 min. on each side or until golden brown on both sides, gently pressing down tops of sandwiches with spatula to flatten slightly as they cook.
