Preheat the oven to 200C/400F/Gas 6.
Heat the groundnut oil and butter in a large, deep casserole dish with a lid over a medium heat.
When butter starts to bubble, carefully add the chicken pieces (in two batches if necessary so as not to overcrowd the pan) and fry them until they are golden-brown on each side.
Lift the chicken out of the pan and set aside. If the butter and oil mixture in the pan is still in reasonable condition keep it for further cooking. If it looks a bit dark, pour it out and add some more, but on no account get rid of the sticky bits on the bottom as that is where much of the flavour is.
Place the chicory into the pan and return to the medium heat. Add the sugar and season with salt and freshly ground black pepper. Cook over a moderate heat for 5-6 minutes, until the outside leaves start to caramelise and soften.
Add the shallots and lemon juice, then return the chicken to the pan. Add the wine to the pan, bring to a simmer, then turn the heat down and cook for ten minutes, or until the wine and cooking juices have reduced.
Add the crème fraîche, season with salt and freshly ground black pepper, and stir the pan juices into the cream. Cover with a lid and transfer to the oven to cook for 50-60 minutes. Stir the pieces of chicken and chicory half-way through this cooking time.
Lift the chicken and chicory out of the sauce with a slotted spoon, place into a serving dish and keep warm.
Add half of the parsley to the sauce and place over a moderate heat. Bring to the boil, then simmer until the sauce starts to thicken slightly - it should be the consistency of double cream.
Add the remaining parsley and stir well. Pour the sauce over the chicken and chicory in the serving dish.
To serve, spoon the chicken pieces and sauce onto plates and serve with boiled potatoes to soak up the juices.