1/2 yellow onion
1 dozen big leaves of kale, chard, or other greens

Soak greens in lightly salted water for 15 minutes, rinse well, drain. Cut lengthwise and then crosswise 1 inch, including the stems.
Over medium heat, sweat thinly sliced onions in olive oil until tender and translucent. Raise heat to high and add the greens. Raise heat to high and add the greens. Cooking, turning occasionally until wilted and tender, about 8-12 minutes, covering part of the time to speed cooking. Fold in salt and pepper to taste, cool slightly, and serve.