Roast Leg of Lamb Recipe with Caper Butter and Mint Sauce

How to cook the perfect roast leg of lamb

  • serves 8
  • Easy

Roast lamb is a classic Easter Sunday favourite – here’s how to get it juicy and pink on the inside, and beautifully crisp on the outside


*This recipe is gluten-free according to industry standards

Follow these easy steps to a successful roast leg of lamb


How to prepare lamb

Removing the lamb from the fridge an hour before roasting allows it to come up to room temperature, meaning more even cooking throughout the joint.


Salting lamb

Salting the lamb before cooking does two things: firstly it draws moisture from the surface of the meat, allowing salt to enter and season it (those salty crispy bits on the outside); secondly, the salt affects the protein structure, which softens and tenderises the meat.

Roast Leg of Lamb - Salting


How to create juicy lamb – butter

Leg of lamb is a relatively lean cut – adding a thick layer of butter to the outside of the meat helps it to remain moist during cooking, while also being a great method of getting flavour into the meat.

Roast Leg of Lamb with Caper Butter and Mint Sauce


How long to cook lamb

To get the lamb to be cooked perfectly medium, with a juicy pink centre, it needs to be roasted for 15 minutes per 500g.


Which roasting tin to use for lamb

This needs to be slightly shallow so that it holds the butter but doesn’t enclose the joint too much and prevent the hot air from circulating around the meat.


How to create juicy lamb – resting

All meat should be rested after cooking – this helps to redistribute the juices back through the meat fibres. If you carve the joint before allowing it to rest, all the juices will spill out, leaving behind dry, chewy meat.

Try our recipe for homemade mint sauce to accompany your roast lamb.



  • leg of lamb 2kg
  • vegetable oil 1 tbsp
  • sea salt flakes 1 tbsp
  • unsalted butter 100g, softened
  • garlic 3 cloves, roughly chopped
  • rosemary finely chopped to make 1 tbsp
  • capers 2 tbsp


  • mint a bunch, leaves picked
  • olive oil 4 tbsp
  • red wine vinegar 1-2tbsp
  • Dijon mustard 2 tsp
  • caster sugar a pinch
  • shallot 1, finely chopped


  • Step 1

    Remove the lamb from the fridge 1 hour before cooking, and very lightly score the meat with a sharp knife in a criss-cross pattern all over. Drizzle very lightly with oil to coat and then sprinkle all over with the salt and leave to marinate for 1 hour. Put the butter, garlic and rosemary into a small food processor and whizz until smooth. Add the capers and pulse several times to mix and slightly break up. Rub the caper butter all over the lamb, to coat evenly.

  • Step 2

    Heat the oven to 200C/fan 180C/gas 6. Put the lamb into a shallow roasting tin and cook in the oven for 1 hour, basting with the caper butter halfway through. If you have a digital thermometer, probe the lamb in the thickest part – it should read between 50-55C. Put the lamb onto a plate, pouring over all of the caper butter and loosely cover with foil to rest for 20 minutes or until it hits a temperature of 60C, before carving.

  • Step 3

    Meanwhile, to make the mint sauce, put the mint leaves into a food processor and pulse briefly to chop and bruise. Add the olive oil, vinegar, mustard, sugar and a little seasoning, and whizz until smooth. Pour into a serving bowl and stir through the chopped shallot. Serve with the lamb and caper butter.

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Nutritional Information

  • Kcals 566
  • Fat 40.5g
  • Saturates 17.4g
  • Carbs 1.1g
  • Sugars 0.5g
  • Fibre 0.3g
  • Protein 49.2g
  • Salt 2.6g