Remove rind from ham. Preheat oven to 180ºC . Place ham on rack in large roasting pan. Make 1 cm deep crisscross cuts in fat atop ham. Heat half of pear puree in heavy small saucepan. Brush some generously over ham. Bake ham until thermometer inserted in thickest past without touching bone registers 60ºC , basting occasionally with pear puree, about 2 hours. Remove from oven and baste again. Let stand 20 minutes. Transfer ham to platter. Pass remaining pear puree separately.