Slash a criss-cross pattern on both sides of the lamb and cut through the membrane about 2mm deep.
Slash a criss-cross pattern into the meat and spread with seasoning paste.
Rub the lamb all over with a little olive oil and Garlic Pepper Seasoning. Mash together all the seasoning paste ingredients adding the oil from the anchovies. Rub into the leg of lamb.
Leave to stand at room temperature. Can be done the night before, but then refrigerate.
Position the oven rack one shelf below the middle and preheat the oven to 150°C. Build a platform in a roasting pan with the onions, thyme, garlic and cloves. Place the prepared leg on top. Pour the wine in on the side. Wet two lengths of baking paper long enough to hang over the sides of the pan. Cover the leg with the sheets of wet baking paper, tucking it under the lip of the pan all round, or tie it around the pan with string.
Position the leg on the platform of vegetables.
Place in the oven to bake slowly for ± 4½ hours.
Make a gravy with the pan juices, thickened a little with potato or cornflour mixed with water. Add lemon juice and a pinch of sugar, stir in a knob of butter. Taste, add a little water if too concentrated.