Chop chard small, removing stems, wash, and dry.

Heat oil in pan. Saute chard lightly, just until softened slightly, and reduced. Add minced herbs and salt, stir well, and set aside to cool slightly.

Butterfly the pork roast, and pound it just enough to flatten. Distribute chard mixture over meat, then roll up and secure.

Cook in a slow cooker on Low for seven hours.

Let rest ten minutes before slicing and serving.