Cut duck into joints, remove all skin, dip the joints in seasoned flour. Place duck, chopped mushrooms and chopped shallots in a casserole. Just cover with stock, put on a tightly-fitting lid and cook in a fairly hot oven (375°–400° F., Gas 5–6) about ¾ hr. Add shelled peas and mint and continue cooking until duck is tender—about another ½ hr. Correct seasoning. Serve from the casserole.