Heat the oil and butter in a deep sided frying pan. Add onion and cook over medium heat until lightly browned and soft. Stir in mushrooms and cook until softened.
Pour in the wine and let the mixture simmer for a few minutes before turning the heat down to low. Stir in the turkey, spring onions, cream, mustard and thyme and continue to cook gently for another 5 or 10 minutes.
Season with salt and pepper then garnish with fresh parsley.