Step 1

Preheat the oven to 200C/180C Fan/Gas Remove the lamb from the fridge and allow it to get to room temperature.

Step 2

To make the garlic butter, place the garlic and butter in a bowl. Add the rosemary to the bowl. Season with salt and pepper and mash to a paste with a fork.

Step 3

With a sharp thin knife or a metal skewer, make between 30 and 50 small incisions into the flesh of the lamb. They should be large enough for you to stick just your fingertip into. Work the butter mixture into the lamb by massaging it into the meat, trying to work it into the holes that you've created.

Step 4

Place the lamb in a roasting tin, cover loosely with foil and place in the preheated oven. As it heats up, the butter will melt and help the rosemary and garlic to work their way into the holes and really penetrate the lamb. After 30 minutes, remove the foil and leave to roast for a further 50–60 minutes for medium or until cooked to your liking. Remove the lamb from the oven and leave to rest for 10–15 minutes, with some foil on top to keep it warm.

Step 5

To make the gravy, heat a heavy-based frying pan on the hob. When hot, pour the pan juices from the roasting tin into the pan (be careful as it may splatter). Add the red wine. Turn the heat down and leave the sauce to reduce.

Step 6

To thicken the sauce, make a beurre manie by mixing together the flour and butter in a clean bowl to make a paste. Add about a teaspoon of the beurre manie to the pan and whisk well, until the sauce has the desired consistency. Add more if needed.

Step 7

To serve, slice the lamb, pour over the gravy and garnish with rosemary. This would be good with potatoes dauphinoise and fresh vegetables for a Sunday lunch.