Put the chicken wings in a pan with the wine, thyme, mushrooms and stock. Bring to the boil and simmer for 30 minutes.
Strain the stock into another pan. Trim off any excess skin from the wings and place the wings on a baking tray. Cover with cling film and then place another tray on top of that. Place weights on top and press and chill in the fridge until needed.
Pass the stock through a fine sieve into a clean saucepan. Place over a medium heat and cook until the volume of liquid has reduced by half. Stir in the crème fraîche, double cream and season with salt and pepper. Blend with a hand blender until foam appears. Keep warm until ready to serve.
Preheat a griddle pan to hot. Remove the bones from the wings, then griddle until crisp all over.
To make the croquettes, pass the potato through a potato ricer. Add one egg, the butter and the camembert. Mix well.
Beat the remaining egg in a shallow bowl.
Roll the potato mixture into cylinders, then roll in the flour, then the beaten egg and then the breadcrumbs.
Preheat a deep-fat fryer to 180C (CAUTION: hot oil can be dangerous. Do not leave unattended.) Deep-fry the croquettes until golden-brown.
Divide the velouté between two deep bowls, shave over a little truffle and serve with the griddled chicken and the croquettes.