Trim away and discard the tough stems of greens. To loosen grit, place the leaves and the remaining tender stems (you should have about 2 quarts) in a large bowl, cover with lukewarm water, and soak for 5 minutes. Rinse several times in lukewarm water to wash away any remaining sand. Melt lard in a large, heavy, nonreactive pot with a lid. (Do not use an aluminum pot; if possible, use one with an enamel coating.) Add onions and bacon. Fry together over medium-high heat, stirring often, until onions wilt and bacon starts to brown (about 5 minutes).
Add greens and the water and bring to a boil over high heat. Cover, lower heat to medium, and cook until greens are tender, with just a little crunch (about 20 minutes).
Uncover, raise heat to high, and boil off some of the excess water (about 5 minutes). Add salt, pepper, and hot sauce to taste, and serve hot (dish should be slightly soupy).
Serves 6.
Notes: Contrary to rumor, greens do not need hours of boiling in a sea of liquid, as this Mississippi recipe proves. What they do need, however, is the flavor of smoked slab bacon or ham; if you must substitute ordinary bacon or ham, you'll need twice as much. Greens are the traditional accompaniment to pork or ham; they also pair up well with corn bread or candied yams.