FOR THE SOUP
2 shallots, finely chopped
100g butter, at room temperature
400g wild mixed mushrooms, trimmed and cleaned, or use 250g mixed dried mushrooms
300ml chicken or vegetable stock
FOR THE GARNISH
100g wild mushrooms, trimmed and cleaned
50g shelled hazelnuts, toasted if you like
Sweat the shallots in half the butter with a pinch of salt for 3-5 mins or until very tender but not coloured. Add the mushrooms and sweat for 5 mins. Pour in 600ml water and the stock and bring to the boil. Season well.
Reduce the heat, cover partly with a lid and simmer gently for 20 mins or until the mushrooms are very tender.
Meanwhile, for the garnish, melt 25g of the remaining butter in a frying pan and sauté the mushrooms and hazelnuts for 2-3 mins.
Pour the soup into a liquidiser and blend until smooth. Rinse out the pan and pour the soup back in. Using a handheld blender or whisk, whisk in the final bit of butter. Taste and adjust seasoning if needed, then ladle into bowls. Garnish with the sautéed mushrooms and hazelnuts.