Brown the meat and onion, then drain. Add the meat and the beans together.
Add the seasoning packet.
In a separate bowl combine the sour cream and soup and mix it together.
Spray the bottom of your casserole dish with non stick cooking spray.
Spread a layer of the soup mixture in the bottom of the pan.
Tear up half the tortillas in big sections and layer them over the soup mixture.
Spread 1/2 the meat and beans mixture as the next layer.
Add a layer of shredded cheese.
Optional: Add hot sauce as the final layer
Repeat the layers one more time to complete the casserole.
Top with shredded cheese and bake it uncovered for about 20 to 25 minutes minutes at 350 degrees.
Note: This recipe was able to serve my family of four two times.