Wrap tortillas in aluminum foil; bake at 350 for 15 minutes. While tortillas bake, coat a large nonstick skillet with cooking spray; place over medium-high heat until hot.
Add onion, cilantro, and jalapeo; saut until onion is tender.
Add chicken and 1 can enchilada sauce; cook 5 minutes.
Spoon chicken mixture evenly down centers of tortillas.
Roll up tortillas; place, seam sides down, in a 13- x 9-inch baking dish.
Heat remaining 2 cans enchilada sauce in a saucepan; pour over enchiladas, and top with cheese.
Bake at 350 for 10 minutes or until enchiladas are thoroughly heated and cheese melts.