You can cook it hot and fast or low and slow but use the same general technique for both.
Make yourself a mix of chopped Garlic, Thyme, Rosemary, Sea Salt, Olive oil, rub down the inside and outside of the lamb, (after you've taken the wool off!
), give it almost enough over the shoulders and saddle to call it a crust.
If you're going hot and fast, you need your pit up to 400 - 450 F cook it till the meat over the shoulders starts to crack or you hit 145 F internal in the thickest part of the shoulder or leg.
If you're going low and slow, cook it at 225 - 250 F, until you get to 145 internal.
As a sauce, use fresh mint, malt vinegar and granulated sugar, for 2 cups of vinegar, 1 cup of sugar, 1 cup of finely chopped fresh mint, warm the vinegar in a non-reactive pan, dissolve the sugar in the vinegar, allow the mixture to cool to room temperature, add the mint, you now have 4 cups of mint sauce.