Preheat the oven to 325 degrees F. Season the lamb with salt and pepper. Spread the flour on a shallow-sided plate; lightly coat the lamb in the flour. Place the oil in a large skillet set over medium-high heat. Shake excess flour from the lamb, and then brown well on all sides. Set the shanks in a single layer in a casserole.
Place remaining ingredients, except peas, in a bowl and mix to combine. Pour mixture over lamb. Cover and bake the lamb 2½ hours, or until very tender. Uncover and skim fat from the surface of the lamb. Sprinkle the peas over the lamb. Heat through in the oven 5 minutes, and then serve.
Note: Diced in this recipe means to cut into ¼–½" cubes. 1 large carrot, diced, should yield 1 cup.