Preheat the oven200C/180C fan/gas 6. In a large, deep, oven-proof frying pan, warm the oil over a medium-high heat. Season the chicken legs and thighs well with salt and pepper before laying the chicken skin-side down in the hot pan.
Allow the chicken to cook for 4 - 5 minutes (avoiding touching, turning and lifting) until the chicken skin is beautifully golden and crisp. Carefully turn the chicken pieces over and allow to cook for a further 4 minutes. Remove from the pan and set a side on a plate.
Top and tail 4shallots and discard the peel. Slice the shallots and fry in the chicken pan for 3 - 4 minutes until they begin to soften (there should be enough fat from cooking the chicken, but if the pan is looking a little dry, add a dash of oil). Add the garlic along with a pinch of salt and allow to fry for a further minute.
Sprinkle in the flour and stir through the shallot mixture. Whilst continuously stirring, allow to fry for 1 minute before adding the creme fraiche, cream and stock to the pan. Bring the pan to a rapid boil before turning down the heat to medium and allowing to simmer gently for 5minutes until the sauce begins to thicken. Remove from the heat.
Finely chop the stalks of the parsley and add to the pan - reserve the leaves for later. Add the white wine vinegar and any cooking juices from the chicken plate and stir well. Nestle the chicken back in the sauce but ensure the golden, crispy skin is above the sauce so it can continue to crisp in the oven. Peel and slice in half the remain shallots - scatter in the sauce.
Place the chicken in the oven and bake for 25 minutes until the sauce is thick and the chicken is cooked through. Season the pan with some cracked black pepper and sprinkle with the reserved parsley. Serve straight to the table alongside seasonal greens and potato of choice.