Place the chicken in the base of a large tagine or heavy-based saucepan and add the onion, carrots, garlic, cloves, cardamom pods and peppercorns. Pour in just enough water to come up the sides of the tagine base to halfway up the chicken and bring to the boil, then reduce the heat, cover and cook gently for 40 minutes, turning the chicken in the stock once or twice during this time.
Meanwhile, use your hands to crush the dried mallow and place them in a heatproof bowl. Pour over just enough boiling water to cover and leave to stand for 30 minutes.
Drain the mallow leaves and add them to the tagine or saucepan. Re-cover and cook gently for a further 30 minutes.
Lift the chicken out of the tagine or saucepan and set on a chopping board. Using a sharp knife, remove the skin and cut the chicken into joints.
Season the cooking liquid and return the chicken joints to the tagine or saucepan. Toss the chicken joints gently in the cooking liquid for 2–3 minutes to heat through. Serve with chunks of bread or couscous, if liked.