Put enchilada sauce and sour cream in saucepan. Drain and rinse black beans and add. Heat through.
Cut tortillas in strips.
Reserve one cup of enchilada sauce on side for top of casserole. Cover bottom of 2.5 quart covered casserole with enchilada sauce mixture.
Add chicken and black beans to remainder of enchilada sauce in saucepan.
Cover sauce in bottom of casserole with layer of tortilla strips (I used two of the tortillas for this layer). Cover tortilla strips with cheese. Add sauce, chicken and bean mixture on top of cheese. Sprinkle liberally with chopped onions and black olives. Add layer of cheese. Cover cheese with remainder of tortilla strips (I used four tortilla)
Top with remaining one cup of sauce, layer of cheese and sprinkle top with chopped onions and sliced jalapenos.
Bake covered 30 minutes then remove casserole cover for remaining 10 minutes of cook time.