Roast Lamb

How to cook Roast Lamb…

Roast lamb is a dish that tends to be associated with the United Kingdom, New Zealand, and Australia, but is also popular in many other parts of the world. Good lamb has a distinctive flavour of its own, however it is also capable of standing up to strong herbs and spices. The classic partnership is with rosemary and garlic, but Moroccan and even Indian spice blends can also work well with roast lamb.

Choosing lamb for roasting…

Fortunately, lamb is not a type of meat that tends to be produced using intensive farming techniques. For this reason the “baseline” quality of lamb tends to be higher than that of other types of meat.

Nevertheless, the flavour of lamb can vary considerably depending on factors such as the breed of the lamb, it’s age at slaughter, and it’s diet. The latter is particularly important in the case of “Marsh Lamb” or “Agneau de pré-salé” which is allowed to graze salty marsh land has a very distinctive taste as a result.

Although good quality lamb can be found in supermarkets, local butcher’s shops and specialist Internet suppliers can be a better place to look. It is also possible to buy lamb directly from local farmers in many areas. I often buy half a lamb from a local farmer in Sussex giving me a couple of good roasting joints (leg and shoulder) as well as a generous quantity of chops and a neck fillet.

The suggested roasting times on this page are for the traditional roasting joints for lamb – the leg and the shoulder. However other cuts can also be roasted, such as rack of lamb, and saddle of lamb.

Roasting the lamb…

Rub a little olive oil over the joint of lamb to be roasted (leg or shoulder) and season with salt and a generous amount of pepper. Optionally, cut slits in the lamb with the tip of a sharp knife and push a slither of garlic into each slit – pieces of rosemary and anchovies can also be inserted into the slits for extra flavour.

Lay the lamb into a lightly oiled roasting tin and place it in a hot oven (220°C / Gas Mark 7). This high temperature “sizzle” is maintained for 30 minutes before turning the oven temperature down to 160 °C (Gas Mark 3) for the remainder of the cooking time, as shown in the roasting summary below:

1. Preheat oven to 220°C (Gas Mark 7).
2. Roast for 30 minutes at 220°C (Gas Mark 7).
3. Reduce oven temperature to 160 °C (Gas Mark 3) and continue to roast for:

  • Rare – 20 minutes per Kg (9 minutes per pound)
  • Medium – 30 minutes per Kg (14 minutes per pound)
  • Well Done – 40 minutes per Kg (18 minutes per pound)

4. Remove the joint from the oven and rest for 20-30 minutes before carving.

Slow Roast Lamb

An alternative approach when roasting lamb is to roast it for longer at a low temperature. This results in a very tender dish with a “melt in your mouth” texture and the lamb literally falls off the bone.

The lamb should be seasoned as described in the standard roasting method (above) and optional slits cut for garlic, rosemary etc… and placed in a lightly oiled roasting tray. For even more flavour, the lamb can be placed on top of whole sprigs of rosemary and halved bulbs of garlic in the roasting tray.

The roasting tray should then be tightly covered with tin foil, making sure that it is sealed all the way round to ensure that the cooking juices do not evaporate.

The lamb should then be roasted at a temperature of 160 °C (Gas Mark 3) for three to four hours.

Because the lamb has not benefited from a high temperature “sizzle” at the start of the roasting process it might be necessary to place it under the grill for a few minutes before serving in order to get a  browned, crisp skin.