“This is sooooo lemony,” writes author Tessa Kiros. “It is also a dish that you can really leave in the oven and go out shopping for a while and hardly even think about the fact that you left something in the oven.” The trick, she writes, is to keep turning the lamb while it is marinating, spooning some of the marinade over it occasionally, perhaps every hour or so. Use a large round or rectangular roasting pan. You may need to ask your butcher to hack the leg in one place to make it fit in your pan.

11/2 cups fresh lemon juice (6 to 7 lemons)
1/2 cup olive oil
1 heaping tablespoon dried oregano
11/2 cups water
3 pounds, 5 ounces leg of lamb, bone hacked in one place and hinged, so it fits in the dish
Salt and freshly ground black pepper
23/4 pounds potatoes cut into big chunks

Mix the lemon juice, olive oil and oregano with 11/2 cups of water in a large nonreactive baking dish. Rub the lamb well all over with salt and black pepper and put it in the marinade. Turn it over a couple of times to coat well. Cover with plastic wrap and refrigerate for 24 hours, turning it frequently throughout your waking hours. Preheat the oven to 350 degrees. Transfer lamb and marinade to a roasting pan and cover the lamb with a sheet of parchment paper, and then cover the pan tightly with 3 layers of aluminum foil. Bake for 1 hour. Turn the lamb over, cover again and reduce the heat to 300 degrees. Bake the lamb for an additional 2 hours. Now turn the lamb gently, as it will be very tender. Add the potatoes to the dish and sprinkle a little salt over them. Cover again and bake for 2 hours, turning the potatoes once during this time. Remove the foil, shuffle the potatoes and put back in the oven at 400 degrees. Roast until a little golden here and there, 20 to 30 minutes. Remove from the oven and let the lamb rest for 5 minutes before serving.