Combine potatoes and saffron in a large bowl. Cover with salted water and let stand 30 minutes. Preheat oven to 350°F. Drain potatoes, reserving 3/4 cup plus 1 Tbs. Of the water. Place lamb shanks in a large roasting pan. Arrange potatoes around lamb. Add reserved water and pour oil and lemon juice over lamb. Season with salt and pepper to taste. Cover and bake 1-1/2 to 2 hours, until lamb is tender.
