Rub a little of the oil over the chicken and season well. Place in a shallow baking dish and roast in a preheated oven, 190°C (375°F), Gas Mark 5, for 20 minutes, then a further 20 minutes per pound, or until the juices run clear when the thickest part of the chicken thigh is pierced with a sharp knife.
Meanwhile, heat 1 tablespoon of the oil in a frying pan, add the chorizo and cook for 3 minutes until lightly crisp, then transfer to a bowl. Add the onion to the pan and cook for 5 minutes until softened. Add the onion and cornbread to the chorizo and mix together, then place in a lightly greased medium-sized baking dish. Pour over the stock, cover with foil and bake in the oven with the chicken for 10 minutes, then remove the foil and cook for a further 10 minutes, or until crispy on top.
Rub a little oil over the chillies, then cook under a preheated hot grill for 5 minutes, turning frequently, until charred. Place in a plastic food bag, seal and leave for 5 minutes until cool enough to handle. When cool, peel away the blackened skin and remove the seeds and membrane. Place the flesh in a food processor or blender with 5 tablespoons of the oil and the remaining ingredients and whizz until smooth, then season. Serve with the roast chicken and stuffing.