Preheat the oven to 350°F. Remove the lamb from the oil, Drain, and pat dry with paper towels. Heat the 3 tablespoons of oil in a large sauté pan over medium-high heat. When the oil is very hot, add the lamb, and sear for 1 to 2 minutes on each side. Once browned, transfer to a roasting rack. Put the rack in a roasting pan and transfer to the preheated oven. Cook for about 11/2 hours, turning once, until the internal temperature reaches 140°F on a meat thermometer (medium rare). Note that the meat temperature will rise about 5 additional degrees upon sitting. Transfer the lamb to a serving platter and let rest for at least 15 minutes before slicing.

Prepare the Ragout:
While the lamb cooks, prepare the white bean, fennel, and olive ragout. Heat the oil in a medium sauté pan set over medium heat. Add the fennel and cook, stirring, until tender, about 5 minutes. Stir in the shallots and garlic, cook 30 seconds. Add the tomato and cook another minute. Add the white beans, artichoke, and saffron and cook, stirring, until hot. Add the wine. Allow the wine to reduce by half, then add the stock, lemon juice, and lemon zest. Simmer for 2 minutes. Remove from the heat and stir in the olives, herbs, and olive oil. Season to taste with salt and pepper. Set aside, covered, to keep warm.

Skim the fat from the roasting pan, then place over medium-high heat on top of the stove. Add the Chardonnay to the pan to deglaze, scraping to loosen the caramelized bits from the pan. Simmer until reduced to a rich, natural glaze, about 3 minutes. Remove from the heat. Add the butter and mint to the pan. Add salt and pepper to taste. Serve this meal family style, with the sliced lamb on one platter and the white bean ragout in a bowl.