Roast Leg of Lamb with Lemon & Oregano Potatoes
A 3kg grass-fed, dry-aged leg of lamb, studded with garlic, anchovy and rosemary, roasted until blushing pink and set over a tray of lemon-scented potatoes that crisp in the lamb juices.
The last Sunday of October is when the roast comes back properly: the clocks have changed, the light goes by half past four, and a leg of lamb in the oven is the best excuse to keep the kitchen warm all afternoon. This is a Greek-leaning take on the classic, with the meat pricked with garlic, rosemary and a little anchovy that melts into savoury depth, and a tray of potatoes cooked in lemon, oregano and olive oil until the edges turn burnished and the middles go soft and sharp. It feeds six with ease, carves like a dream, and asks for very little beyond a good thermometer and a bit of patience at the end.
The leg is the whole hind limb of the lamb, from the hip down to the shank, and it is the most reliable roasting joint on the animal. It is made of several large muscles, the topside, silverside and the thick round at the top, which is why a bone-in leg gives you a range of textures from tender and pink in the centre to more fully cooked and savoury near the shank. The bone conducts heat, protects the meat from drying out and gives the gravy its backbone, so we would always choose bone-in for a centrepiece.
When you buy, look for flesh that is a clear, pale-to-mid pink-red rather than dark or grey, with a firm, fine grain. The fat should be creamy white and dry to the touch, and there should be an even covering about 5mm thick, because that cap bastes the meat as it renders. Avoid yellowish, sticky fat, and a leg that has been trimmed too bare. Dry-ageing, as we do, lets the muscle relax and concentrates the flavour, so the lamb tastes deeper and the crust browns more readily.
Our legs come from grass-fed British lamb. The slower, pasture-led growth gives a sweeter, more rounded flavour with a faint herbal note that suits rosemary and oregano. The 3kg leg serves six to eight; the 1.5kg leg suits three or four, and the boneless butterflied option cooks faster and carves in neat slices. Take the joint out of the fridge a good hour before roasting so it goes into the oven at cool room temperature.
- 1 x 3kg Grass Fed & Dry-Aged Leg of Lamb, bone in
- 6 garlic cloves, each cut into 3 slivers
- 3 anchovy fillets in olive oil, torn into small pieces
- 4 sprigs of rosemary, leaves picked into small sprigs
- 3 tbsp olive oil
- 2 tsp flaky sea salt
- Freshly ground black pepper
- 1 lemon, halved
- 1.5kg Maris Piper or King Edward potatoes, peeled and cut into 4cm chunks
- 6 tbsp good olive oil
- 3 garlic cloves, bruised
- 2 tbsp dried Greek oregano
- Finely grated zest and juice of 2 lemons
- 300ml hot chicken or lamb stock
- 1 tsp flaky sea salt
- 1 onion, halved and left unpeeled
- 1 tbsp plain flour
- 150ml dry white wine
- 300ml lamb or chicken stock
- 1 tsp redcurrant jelly
- 15g cold butter
- Small handful of flat-leaf parsley, chopped
- Flaky sea salt
- Thick Greek yoghurt, to spoon alongside
- Bring to room temperature. Take the lamb out of the fridge a full hour before cooking, unwrap it and pat it completely dry with kitchen paper. A dry surface browns; a damp one steams. Set the oven to 220°C (200°C fan) with the shelf in the lower third.
- Stud the leg. With the tip of a small, sharp knife, make about 18 deep incisions, 2 to 3cm deep, across the top and sides of the leg. Push a sliver of garlic, a scrap of anchovy and a small sprig of rosemary into each. The anchovy will not taste fishy; it melts into the juices and works like salt with depth.
- Season and oil. Rub the lamb all over with the olive oil, then the salt and plenty of black pepper, working it well into the fat. Squeeze half a lemon over the top. Place the leg, fat side up, on a trivet of the halved onion in a large, heavy roasting tin and tuck the squeezed lemon halves alongside.
- Parboil the potatoes. Put the potatoes in a pan of cold, well-salted water, bring to the boil and simmer for 8 minutes, until the outsides have just softened. Drain, leave to steam for 3 minutes, then shake the colander hard so the edges roughen. Those rough edges are what crisp later.
- Blast the lamb. Roast the lamb at 220°C (200°C fan) for 20 minutes, until the fat is sizzling and lightly golden. Then reduce the oven to 160°C (140°C fan) and roast for a further 1 hour 30 minutes to 1 hour 45 minutes.
- Dress the potatoes. While the lamb roasts, toss the parboiled potatoes in a large tin with the olive oil, garlic, oregano, lemon zest and salt until every piece is glossy. After the lamb has had 45 minutes at the lower temperature, slide the potatoes onto the shelf above, and cook for 30 minutes.
- Add the lemon and stock. Pour the lemon juice and the hot stock over the potatoes and give the tin a gentle shake. Return to the oven for another 45 minutes, stirring once, until the liquid has been absorbed and the potatoes are tender in the middle and golden and crusted at the edges.
- Check the lamb. Start probing the lamb after 1 hour 30 minutes of the lower-heat roasting. Push a thermometer into the thickest part, avoiding the bone. Take it out at 56°C for blushing pink, or 62°C for medium. It will climb 5 to 6°C as it rests.
- Rest the lamb. Lift the leg onto a warm board, cover loosely with foil and a tea towel, and leave it for 30 to 40 minutes. Turn the oven up to 220°C (200°C fan) and give the potatoes a final 15 minutes while the meat rests, to crisp them hard.
- Make the gravy. Pour off all but 2 tbsp of the fat from the lamb tin, then set it over a medium heat with the roasted onion, crushing it with a spoon. Stir in the flour for 1 minute, add the wine and boil for 3 minutes, scraping up the sticky bits. Add the stock and redcurrant jelly, simmer for 8 minutes, strain, and whisk in the cold butter to gloss.
- Carve and serve. Carve the lamb in thick slices parallel to the bone, turning the joint as you go, and pour any resting juices into the gravy. Pile the potatoes onto a platter, scatter with parsley and a little flaky salt, and serve the lamb with the gravy and a bowl of yoghurt.
A large roast fails when the outside is cooked long before the middle is ready. Starting at 220°C gives the fat cap a fast burst of heat so it renders and the surface browns through the Maillard reaction, which builds the roasted flavour. Dropping to 160°C then lets the heat travel slowly towards the centre, so the meat cooks evenly with only a narrow band of well-done meat under the crust.
Resting matters more than it looks. While the lamb is in the oven, the muscle fibres tighten and push moisture towards the middle. Over 30 to 40 minutes off the heat the fibres relax, the temperature evens out and the juices thicken slightly, so they stay in the slices instead of flooding the board. The carry-over rise of 5 to 6°C is why we pull the joint early.
The anchovy is there for glutamates, which amplify the savoury taste of the lamb without announcing themselves. The lemon and oregano cut through the richness of the fat, and the parboiling gelatinises the potato surface, so it dries into a crisp shell when the stock reduces.
If you cannot get a whole leg, a 1.5kg leg serves four and needs about 1 hour 10 minutes at the lower temperature. A boneless butterflied leg also works: marinate it in the same flavours, roast at 200°C (180°C fan) for 45 to 55 minutes, and check from 40 minutes. A shoulder of lamb will give a softer, more pulled result, but needs far longer at a lower heat.
Swap rosemary for thyme or sage, and use fresh oregano in place of dried if you have it. If you dislike anchovy, use a teaspoon of Dijon mustard rubbed into the fat. For the potatoes, small waxy Charlotte potatoes keep their shape, and sweet potato halves or chunks of celeriac are lovely with the lemon.
Vegetarian guests can have the potatoes with a tray of roasted aubergine, peppers and halloumi, cooked in the same lemon and oregano dressing.
The lamb can be studded and seasoned the day before; cover loosely and keep it in the fridge, then bring it out an hour before cooking. The potatoes can be parboiled and roughed up in the morning and kept cold. Leftover lamb keeps for 3 days in the fridge, wrapped well, and is excellent sliced thinly in flatbreads with yoghurt, or shredded into a pie. To freeze, slice and freeze in portions with a little gravy for up to two months, defrost overnight in the fridge, and reheat gently, covered, at 150°C (130°C fan) for 15 to 20 minutes. The potatoes are best eaten fresh, but will re-crisp in a hot oven for 10 minutes.
- Roasting straight from the fridge. A cold 3kg joint will cook unevenly, with a grey, overdone outside and a raw centre. Give it a full hour on the side first.
- Guessing the timing. Ovens vary and so do joints. A probe thermometer removes the guesswork, and 56°C pulled from the oven is the difference between pink and overcooked.
- Carving too soon. Cut it straight from the oven and the juices run onto the board. Rest it for at least 30 minutes, under foil and a tea towel.
Slice the garlic into slivers rather than crushing it. The slivers hold their shape inside the incisions and soften to sweet, mellow nuggets rather than burning on the surface.
Wine: a medium-bodied red with some savoury grip, such as a Nemea Agiorgitiko or a good Rioja Crianza. Beer: a malty amber ale or a pale English bitter. Non-alcoholic: chilled pomegranate juice topped up with sparkling water and a sprig of mint.
Steamed greens dressed with lemon and olive oil, or wilted spinach with nutmeg, balance the richness of the lamb. A Greek-style salad of tomato, cucumber and red onion, a bowl of mint sauce and a jar of redcurrant jelly all earn a place on the table. Warm flatbreads or crusty bread are good for mopping the gravy, and roasted carrots with honey and thyme suit the season. For pudding, a baked quince or apple crumble with custard finishes the afternoon.
How long does a 3kg leg of lamb take to roast?
About 2 hours in total: 20 minutes at 220°C (200°C fan), then 1 hour 30 to 45 minutes at 160°C (140°C fan), for pink meat. Use a probe and remove the joint at 56°C for pink or 62°C for medium, then rest for 30 minutes.
Should I roast leg of lamb covered or uncovered?
Uncovered, so the fat renders and the surface browns. If the top darkens too quickly, tent it loosely with foil for the last part of cooking, but remove the foil before resting so the crust stays crisp.
What temperature should lamb be cooked to?
Remove at 56°C for pink, 62°C for medium and 68°C for well done. The temperature rises by about 5 to 6°C while it rests, so it is better to pull the lamb slightly early.
Can I cook the potatoes in the same tin as the lamb?
You can, but they will steam in the juices and turn soft. Cooking them in a separate tin on the shelf above gives you crisp, golden edges, and you can make the gravy from the lamb tin at the end.
How much leg of lamb per person?
Allow 400 to 450g of bone-in lamb per person, which gives a generous portion and a little left over. The 3kg leg serves six to eight; the 1.5kg leg serves three or four.
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