Preheat your oven to 120 ° C.
Brown the lamb shank in a cast iron casserole with a good drizzle of olive oil on all sides.
Meanwhile, prepare the vegetables. Peel the onions, slice them. Detach the cloves from the garlic heads and crush them lightly with the flat of a knife. Peel the carrots and cut them half round.
Deglaze the meat with the white wine.
Remove the meat from the dish, rub the bottom of the pan well with a wooden spatula to recover all the juices. Pour the juice into a bowl, add a few turns of pepper and half a teaspoon of coarse salt.
Fry the vegetables in a good drizzle of olive oil until the onions lightly color. Add meat, gravy, thyme and rosemary, cover and put in the oven for 3 hours. Monitor the cooking regularly and add a little water if necessary.