Wash the chard and chop or tear into peices, discarding tough stems. Saute tomatoes over medium heat in large skillet until cooked to desired consistancy, 5-15 min. (I like mine on the soft side). Add vinegar, chard and water if needed. Cover and steam vegetables until cooked to desired doneness, 5-15 min. Check occasionally to be sure there is enough water in the pan.

Cooking time for tomatoes and greens depends on how tough the greens are, smaller, younger leaves will be more tender; and how well cooked you like the vegetables.