Brown the cube steak over Medium heat on both sides.
Prepare the soup in a pot according to package direction. Heat through.
Add sour cream to the mushroom soup and stir until incorporated.
In the crock pot, layer a bit of soup mixture, cube steak, soup, cube steak and top with remaining soup mix. (You may also just dump the soup mixture over the cube steak in the crock pot).
Cook on low for up to 6 hours or high for 3 hours. (crock pot only).