Return the duck legs to the pan, skin-side up, making sure they are nestled into the juices and not sitting on top. Strew with thyme, cover and cook in the centre of the oven for 1 hour. Meanwhile tail and scrub the turnips thoroughly, but do not peel them.
Take the pan out of the oven and add the turnips, dotting them around the duck and shallots. Return to the oven for 40 minutes until the duck is very tender. When done, allow the pot to stand for 10 minutes. Remove the lid and diligently spoon off as much of the excess fat that will be loitering at the top as possible.
Taste, season the gravy and serve. This goes very well with boiled pearl barley tossed through with chopped parsley, pepper and a smidgen of butter.