Swiss chard has always had an unpleasant bitter taste on my palate, but it is high in nutrients so I work with it to make it more tolerable to my palate. My most recent experiment:
1 bunch rainbow Swiss chard
1Tbsp. coconut oil
1/2 oz. raisins
1/2 oz. pecans, chopped
Heat oil in pan, add raisin and pecans, sauté 1 minute, add Swiss chard (chopped), sauté 7 minutes until limp. Salt to taste.
The sweetness of the raisins helps to subdue the bitter greens. The pecans add a great crunch and the coconut oil gives it a smooth finish.