How to Make It
Preheat the oven to 325°. Season the lamb with salt and pepper. In a large roasting pan set over 2 burners, heat 1/4 cup of the olive oil until shimmering. Add the lamb and brown it over moderate heat on 4 sides, about 7 minutes per side. Transfer the lamb to a large plate and pour off the fat from the roasting pan.
Return the lamb to the roasting pan. Add the white wine and water and bring to a boil. Add the rosemary, thyme, marjoram and sage sprigs. Cover the lamb with parchment paper, then cover the pan with foil. Braise the lamb in the oven for 2 1/2 hours, or until very tender, turning it halfway through.
Transfer the lamb to a cutting board and cover it with foil. Pour the braising liquid into a large saucepan and skim off the fat. Boil over high heat, skimming occasionally, until reduced to 4 cups, about 30 minutes.
Meanwhile, in a medium saucepan, boil the red wine over high heat until reduced to 2/3 cup, about 7 minutes. Strain the reduced lamb-braising liquid into the red wine reduction. Add the remaining 2 tablespoons of the olive oil and boil over high heat until reduced to 2 1/2 cups, 10 to 15 minutes. Season with salt and pepper.
Cut the strings from the lamb roast and discard. Slice the lamb 1/2 inch thick and transfer to plates. Ladle the jus over the lamb and serve right away.