Modified web recipe, I think this is the best flavor combo I've ever gotten from Swiss Chard, the savory/sweet balance is amazingly tasty:

Sweet and Savory Sauteed Chard

2 bunches swiss chard (about 3 cups)
1 large clove garlic, crushed
1 small onion sliced into strips
1 tb olive oil
1 tb butter
2 tb quality basalmic vinegar
1/2 c dried cranberries (aka Craisons)
salt and pepper to taste

Wash and rinse chard well, then cut off stems into 2" lengths, set aside, slice the leaves into 1" wide strips.

Heat large skillet to med heat, add oil and butter. Saute the onions and garlic until translucent (4-6 min) then add the stems and cook another 4-5 min, then add the leaves and saute until wilted and soft, Add the cranberries and basalmic and salt and pepper, saute one more minute then serve. Note: you can add/substitute beet greens if needed, they are the same taste.

great,food.