How to Roast Lamb
A beautifully roasted lamb turns any meal into a special occasion. Follow this step-by-step guide to learn how to roast lamb to perfection every time.
Season to taste
First trim some of the excess fat off the joint if you wish. Chop up herbs or garlic and rub the mixture evenly over the surface of the lamb. Use whatever herbs or seasonings you like but don’t salt the lamb until just before roasting, as salt can draw moisture from the meat and make it tough.
Infuse for best flavour
Wrap the coated meat tightly in cling film and chill it in the fridge overnight for best flavour.
Another popular way with lamb is to make small incisions in the surface of the meat and push slivers of garlic and sprigs of rosemary into the slits. You can do this right before you begin roasting, or do it a day ahead of time for a more intense flavour.
Before roasting your lamb, take it out of the fridge and let it sit for 30 minutes. A joint at room temperature will roast more evenly. Also, using a roasting rack will ensure even browning and heat circulation.
Roast to perfection
The amount of fat that your lamb has surrounding the outside and marbled through the middle will determine the cooking time and temperature you use.
For a lean piece of meat, cook at 230°C / Gas 7-8 for the first 15 minutes, then turn the temperature down to 180°C / Gas 4 to continue. The lamb should take about 25 minutes per 500g to cook to medium rare.
Using a hot oven in this manner will allow joints with less fat to get nicely browned on the outside before they become overcooked and dry in the middle.
For a roast with more fat, cook at 160°C / Gas 2-3 for a longer period of time, allowing the fat to slowly melt and bathe the joint in its own juices. Meat cooked with this method will take about 30 minutes per 500g to reach medium rare.
To be exact…
You can also tell the temperature of your lamb using a meat thermometer. Some cooks prefer this, as it takes the guesswork out of roasting. Follow these temperatures for lamb based on your preference:
Rest before carving
Once you remove the lamb from the oven, cover it with foil and allow it to rest for 15 to 20 minutes. As the lamb rests, it will continue cooking, the muscle fibres will relax and the juice that has come to the surface of the meat during cooking will begin to return to the centre. A well-rested joint will be more tender and will retain its juices better when you carve it.