Slow Roast Lamb2/5 (161 ratings) By Matt Dye
When cooked to perfection lamb tastes delicious. This slow roast lamb recipe will excite you whilst you carve.
- 2.5kg leg of lamb
- 2 fresh rosemary sprigs, leaves picked and chopped, plus extra to garnish (optional)
- 1 heaped tbsp. sea salt
- 2 garlic cloves, roughly chopped
- Olive oil, for drizzling
- 1 tsp. plain flour
- 600ml fresh lamb or chicken stock, hot for the boulangere potatoes
- 1 small onion
- 1 fennel bulb
- 850g floury potatoes
- 25g butter, plus extra for greasing
- 3 garlic cloves, finely sliced
- 250ml vegetable or chicken stock, hot
- Preheat the oven to 230°C/ fan210°C/gas 8. Calculate the roasting time (a 2.5kg leg of lamb, cooked this way should take just under 4 hours). Using a small, sharp knife, make small 2.5cm-deep slits all over the meat, 5cm apart. Put the rosemary leaves, sea salt, garlic and black pepper into a pestle and mortar, and crush together until it’s a rough green salt. Rub the rosemary salt all over the lamb leg, pushing plenty into the slits. Set aside.
- Make the boulangère potatoes. Halve and very thinly slice the onion. Halve the fennel bulb and cut out the hard core. Lay flat-side down and very thinly slice. Peel and very thinly slice the potatoes. To stop them going brown, cover with damp kitchen paper but don’t put in water, or they’ll curl up like crisps. Butter a 20cm x 30cm shallow, ovenproof dish. Layer up the potatoes, garlic, onion and fennel, finishing with the potatoes. Dot with the butter and pour over the stock.
- Put the leg of lamb, rounded side up, in a roasting tin, drizzle with oil and roast the lamb in the oven for 15 minutes. Lower the oven temperature to 180°C/fan160°C/ gas 4, cover with foil and cook for another 2½ hours. Put the potatoes on a lower shelf and cook for a further 1 hour. Check that the potatoes are not browning too much – cover with foil if they are.
- Turn the oven off and leave the potatoes inside while you remove the lamb to a board. Keep covered with foil and rest for 15-20 minutes before carving.
- Meanwhile, make the gravy. Pour away the excess fat from the roasting tin and place over a medium heat. Sprinkle with the flour and stir into the meat juices with a wooden spoon. Gradually add the stock and scrape up all the caramelised juices in the tin. Simmer gently until it has reduced to well-flavoured gravy. Season and strain into a gravy boat. Carve the slow roast lamb into slices and serve with the gravy and potatoes.