Heat the oil in a flameproof casserole. Sizzle the bacon for 4 mins until crisp. Turn up irish stew 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. 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. This website is published by Immediate Media Company Limited under licence from BBC Studios Distribution. Put the lamb bones in a large heavy-based saucepan with the carrot, onion, celery, herbs, peppercorns and 1 tsp salt. Bring to the boil and simmer uncovered for 2 hours. Strain the stock through a fine sieve to remove bones and vegetables, then return to the pan. Boil until reduced to about 1. Cut the lamb into large chunks.