Found this recipe on a package of chicken breasts, been making it from memory ever since. Very tasty, and very easy. Great weeknight meal with mexican rice and salad. Hearty eaters may want tortillas, too.
Spread beans in a 9" x 13" casserole dish. Lay chicken breasts on top. Pour enchilada sauce over. Sprinkle with cheese.
Baked, covered until chicken is done, about 45 minutes. (Consistency may vary - check after 30 minutes, and uncover if the sauce is too "soupy") Uncover and bake 5 minutes more, just to toast the cheese.