This is a dish I've been cooking for quite a while, it's fab, really tasty and a nice alternative to Sunday roast, we had this for dinner last night. I got the recipe from UKTV Food and it's by Merrilees Parker.
Using a hand blender make a paste with 2 tablespoons olive oil, 1 tablespoon each of ground ginger, cumin & coriander, 2 teaspoons each of turmeric & harissa, juice and zest of 1 unwaxed lemon, 1 bunch coriander stalks and a pinch of salt.
Place lamb shoulder on a large double sheet of foil, cut several incisions in lamb and rub paste all over. Spoon over 2 tablespoons water, wrap foil round lamb leaving a pocket of air, place in a roasting tray and roast for 4 hours at 170 degrees, open foil, baste lamb and cook for another hour. This timing was perfect for my average size lamb shoulder, probably wise to increase for large pieces, it needs to be falling off the bone.
For the tomato salsa, finely chop tomatoes, shallots parsley and coriander leaves and mix with lime juice and olive oil. The original recipe has homemade aioli but frankly there's somethings I'd rather buy or not quite so cheating, roast a whole bulb of garlic with the meat for the last hour, squeeze the soft garlic into a good quality mayonnaise.
Shred the lamb and serve on warm flatbreads or flour tortillas with the salsa and aioli.