Prepare and brine the chicken: Spatchcock the chicken and apply a dry brine of salt. Leave in the fridge for 6-8 hours or overnight.
Prepare the potato pavé: Slice the potatoes thinly, season with salt and thyme, and mix with clarified butter. Layer in a bread tin lined with parchment paper, cover with foil, and bake at 170 degrees Celsius for about 2 hours until fork tender.
Roast the chicken: Place the spatchcocked chicken in a hot, oiled pan, breast side down, and then roast in a 180 degrees Celsius oven until the internal temperature reaches 65 degrees Celsius.
Prepare the endive: Season halved endive with salt, pan-fry cut side down, then add chicken stock and let steam.
Make the sauce: Sauté shallots and garlic in the chicken pan, add grapes, deglaze with white wine, reduce, then add chicken stock. Finish with parsley and red wine vinegar.
Serve: Plate the chicken with the potato pavé and braised endive. Garnish the endive with parmesan and olive oil, and serve the chicken with the shallot and grape sauce.