Choose a new cookbook worth up to £28 when you subscribe to our magazine.
Heat oven to 160C/fan 140C/gas 3. Heat the oil in a flameproof casserole. Sizzle the bacon for 4 mins until crisp. Turn up the heat, then cook the lamb for 6 mins until brown. Remove the meats with a slotted spoon. Add the onions, carrots and herbs to the pan, then cook for about 5 mins until softened. Return the meat to the pan, stir in the pearl barley, pour over the stock, then bring to a simmer.
Sit the chunks of potato on top of the stew, cover, then braise in the oven, undisturbed, for about 1½ hrs until the potatoes are soft and the meat is tender. The stew can now be chilled and kept in the fridge for 2 days, then reheated in a low oven or on top of the stove. Remove from the oven, dot the potatoes with butter, scatter with the spring onions and serve scooped straight from the dish.