Preheat oven to 400ºF. Combine green beans with shallots, oil and lemon zest on heavy large rimmed baking sheet; toss well to combine. Spread beans out into single layer and season with salt and pepper. Roast the beans in the oven until just beginning to brown, about 10 minutes.
Stir the beans well and sprinkle with walnuts and cranberries. Continue to roast until beans are almost just tender, about 6 minutes longer. Add the water and lemon juice and continue roasting until the liquid evaporates and the green beans are lightly glazed, about 4 minutes longer. Garnish with parsley and lemon wedges if desired and serve.