Strip the stems from the leaves of the chard and kale. If you are using the stems cut into bite size pieces and set aside.
Heat up a large fry pan. add oil (or bacon fat if you have it) add stems of chard and kale allow to soften about 5 mins. Add leaves, salt and cover allow to cook for about 5 mins. Tastes and adjust the salt level, add the balsmic vinegar stir well and remove from pan and serve!