Heat the butter and oil in a frying pan, add the chicken and fry until cooked, remove the chicken and set aside.
Add the mushrooms and onions and fry until the mushrooms and onions until soft.
Add the garlic and stir for another few mins. Then add the wine and cook until the liquid is reduced by half.
Add the stock and bay leaf and gently simmer for around 15mins.
Add the cream and crème fraiche, stir together, season and simmer for around 10mins.
Serve immediately with some plain boiled rice or potatoes (hasselbacks would go great with this dinner!)