You will need
Melt the butter, add the mushrooms and cook for 2-3 minutes.
Cover with a lid and simmer for 5 minutes.
Stir in the hazelnuts. Add the stock and season to taste with nutmeg, salt and pepper.
Adjust the consistency by adding a little milk if necessary.
Cover and simmer for 10 minutes. Stir in the cream and reheat gently.
Serve immediately with crusty bread.