Pat the lamb dry with paper towels and season generously with salt and pepper. (See Tips and Tricks; if you have time, season the meat 2+ hours ahead of time to allow the flavor to build.)

Heat the olive oil in a heavy-bottomed pot over medium-high. In batches, sear the lamb, fatty-sides down until browned on both sides, 4 to 5 minutes per side. Transfer the lamb to a plate.

Deglaze with the white wine (if using) and scrape up all the browned bits from the bottom of the pan. Alternatively, deglaze with ¼ cup water. Remove the pot from the heat.

Start to build the dish by placing ⅓ of the lamb pieces into the bottom of the pot. Sprinkle with a generous pinch of salt, a pinch of whole peppercorns, and ½ teaspoon of flour. Arrange ⅓ of the cabbage wedges over the lamb and sprinkle with more salt, peppercorns, and another ½ teaspoon of flour. Repeat with the remaining lamb and cabbage, ending with a layer of cabbage. Finish with more salt, peppercorns, and the remaining ½ teaspoon of flour.

Pour 1 cup of water over the lamb and cabbage. Bring the water to a boil over medium-high heat, then reduce the heat to the lowest setting and let it simmer until the meat is falling off the bone, about 2 ½ hours. (While it may be tempting to initially add extra water, resist the urge as the cabbage releases moisture as it cooks). Check occasionally and add more water as needed, ½ cup at a time if the pot seems dry or if too much of the liquid is evaporating. Remember, you want some broth at the end to spoon over the dish.

After 2 hours, place the potatoes in a medium pot and cover with at least one inch of salted water. Bring the water to a boil and cook the potatoes until fork-tender, 10 to 12 minutes.

Once the meat and cabbage are done cooking, season to taste with more salt. (A good way to taste if it’s salty enough is by tasting some of the liquid at the bottom.) Serve the lamb and cabbage alongside the potatoes, and spoon the sauce and peppercorns over top. Season with more salt and pepper as needed. Garnish with chopped parsley.