Make the flavoured butter first. Place all the ingredients into a bowl, mix well and chill. Remove from the fridge 20 minutes before you need it and set aside.
Now make the couscous stuffing. Heat the olive oil in a saucepan, and sweat the onion for a minute or two. Add the remaining ingredients, except the couscous and parsley. Season the mixture with salt and pepper and stir over a moderate heat for five minutes, adding a little water if it starts to stick. Remove from the heat and stir in the couscous and parsley.
Preheat the oven to 160 °C. Lay the lamb onto a flat surface and open it up gently with a knife. Spread the flavoured butter paste onto both sides of the butterflied lamb. Spread the couscous filling onto the lamb and roll it up tightly, securing with string or toothpicks.
Scatter the casserole base ingredients, except the chicken stock, over the bottom of a casserole dish or deep oven tray. Place the stuffed lamb on top and pour over the chicken stock. Cover with foil and roast in the preheated oven for two-and-a-half hours or until cooked.
TIP: I like to use a few dried apricots, figs, prunes, dates and cranberries for scattering over the base of the casserole dish.
Recipe extracted from Taste the world with Jenny Morris, by Jenny Morris, published by Jonathan Ball. On sale now for R295.