Preheat the oven to 190°C/ 375°F/Gas mark 5.
Season the flour with salt and pepper, and use to coat the duck. Put the shallots and mushrooms with the duck in a casserole dish.
Add enough stock to cover, put on a lid and cook in the oven for 45 minutes. Add the peas and mint and continue cooking for a further 30 minutes until the duck is tender. Serve hot.