Method

Preheat the oven to 180°C/350°F/Gas Mark 4. Place the flour in a shallow dish and season lightly, then use to coat the diced lamb. Arrange half of the lamb in the bottom of a round casserole dish and scatter over half of the pearl barley, then add a sprinkling of thyme. Layer up the onion, leek, carrots and turnip and finish with the rest of the pearl barley, then add another sprinkling of thyme. Arrange the remaining lamb on top to cover the vegetables completely and sprinkle over the remaining thyme.

Pour enough chicken stock to just come up above the last layer of lamb. Cover the casserole with a lid and place in the oven for about 1 hour until the lamb and vegetables are almost tender and the stock has thickened slightly.

Place the potatoes in a pan of boiling water and bring to the boil, then simmer for 10 minutes. Drain in a colander and set aside for 5 minutes until cool enough to handle. Slice the potatoes lengthways into 1cm (½in) thick slices and lay them in a slightly overlapping layer on top of the stew. Brush lightly with the sunflower oil.

Return the stew to the oven and cook for another 40 minutes until the potatoes are cooked through and nicely golden. Serve straight to the table so that everyone can help themselves.