Make the joloff-spiced butter. Pound the garlic, some sea salt, the thyme and lime zest using a pestle and mortar, then add the spices and the butter and pound more. Add the lime juice gradually, then set aside.
To make the stuffing, heat the butter in a saucepan, add the onion and cook until soft. Add the rice and stir for 1 min, then add enough water to cover by about 2cm and bring to the boil. Boil until the surface of the rice looks ‘pitted’, then turn the heat down very low, cover and cook for 15 mins until the rice is almost cooked (it will cook further inside the chicken). Transfer to a mixing bowl and leave to cool. Heat oven to 180C/160C fan/gas 4.
Heat the groundnut oil in a frying pan and cook the sweet potato until golden. Add the garlic and ginger and cook for another 2 mins, then add the tomatoes and season. Cook, stirring often, until the tomatoes are soft and the sweet potato is almost tender. Leave to cool, then tip into the bowl with the rice and add the lime juice.
Put the chicken in a roasting tin and carefully loosen the skin over the breast by gently pulling it up and inserting your fingers between the skin and the flesh. Push half of the butter in under the skin, spreading it out with your hands. Season the chicken inside, then spoon the rice stuffing right down into the cavity. Spread the rest of the butter over the top of the chicken, then season. Roast for 1 hr 20 mins. To check it’s cooked, insert a skewer in where the thigh meets the body – the juices should run clear.
Meanwhile, to make the sauce, heat the oil in a saucepan and cook the onion until soft. Add the garlic, ginger and spices and cook for another 2 mins, then add the water or stock and the tomatoes. Season. Bring to the boil, add the sugar and the chillies, then turn down the heat and simmer gently for 30 mins. Add the peanut butter and cook, stirring, for another 12 mins. Add more water if it’s too thick, then add the lime juice to taste and check the seasoning. You may want to add more sugar.
When it’s cooked, leave the chicken to rest, covered with foil, for 15 mins, then serve with the peanut sauce and green vegetables on the side.
