Heat the oven to 160C/140C fan/gas 3. Heat a little oil in a casserole dish.

Sizzle the legs in the casserole dish, skin-side down, until golden brown. Turn and cook for 10-15 mins to brown them all over.
Remove the duck legs to a plate and pour away half the fat from the casserole.

Return the casserole dish to the heat and fry the carrots celery, garlic sausage and rosemary along with some seasoning until the carrots start to soften.

Sit the duck legs on top, skin-side up.

Pour water over the veg.

Bring to a simmer, cover and transfer to the oven to cook for 1 hr 30 mins.
Remove the casserole from the oven and uncover.

Turn the oven up to 200C/180C/gas 6. Lift the duck out onto a plate and stir the beans through the carrots and thyme. Sit the duck back on top, then return to the oven, uncovered, to cook for until the duck skin is crisp and the beans are simmering.