1Heat oven to 350°F. Lightly spray 11x7-inch (2-quart) glass baking dish with cooking spray. Heat oil in 10-inch skillet over medium heat. Add onion and cumin; cook and stir until onion is tender. Stir in beans.
2Place about 3 tablespoons bean mixture in center of each warm tortilla. Top each with 1/4 cup Monterey Jack cheese. Roll up tightly; place, seam side down, in baking dish. Spoon enchilada sauce over tortillas. Spray sheet of foil with cooking spray; cover baking dish with foil, sprayed side down.
3Bake 30 to 35 minutes or until thoroughly heated. Sprinkle with Cheddar cheese. Serve enchiladas with salsa.