Slow-roasted Shoulder of Lamb with Fresh Herbs

This is adapted from a dish served at Au Bonheur des Tartes, a tiny restaurant in Montpellier – little more than a hole in the wall, with tables outside in good weather. They specialize in the traditional cooking of the south-west. It makes a very impressive main course, especially when served with a gratin of potatoes. Try to get a shoulder that is not too fatty, lamb in the south has much less fat, and marinate it overnight if you can.