1. Put rhubarb in sauce pan with 4 T sweetener and simmer gently until rhubarb is very soft.
2. Separate liquid from rhubarb and save separately. Cool.
3. Whip the cream until soft peaks form, stir in yogurt and 1 T sweetener. Fold in cooled rhubarb.  Cool.
4. Serve in wine or martini glasses topped with rhubarb liquid and mint.

* Remove strings before chopping if desired