The stem is a snowplough turn with a twist: the pressure applied to the outside ski is even more pronounced and the inside ski is lifted from the ground at the end of the turn to then be brought parallel to the outside ski. The leg independence during this phase is complete as the whole weight of the body is distributed over one of the skis while the other ski is lifted up.
Reminder: the outside ski is the one furthest away from the centre of the circle the skier is turning about.