2 tbsp olive oil
2 tbsp butter
1 small onion, chopped
2 tbsp plain flour
1 litre vegetable stock
1 litre milk
a pinch of dried basil
salt and pepper
2 tbsp butter, extra
cream and fresh basil leaves to garnish
Remove the stalks from the mushrooms. Finely slice half the caps; roughly chop the remainder.
Heat the oil and butter in a heavy-based saucepan. Add the mushroom stalks and chopped caps, and the onion. Fry for a minute or two, then cover and sweat over a gentle heat for 6-7 minutes.
Stir in the flour and cook for 1 minute to make a roux. Add the stock and milk gradually to form a thin, smooth sauce. Add basil, salt and pepper to taste. Bring to the boil and simmer, partly covered, for 15 minutes.
Meanwhile, over a high heat, fry the sliced mushroom caps in the extra butter until golden.
Allow the soup to cool*. In a blender or food processor, purée the soup until smooth. Return to the pan and add the fried mushroom; heat until very hot and adjust the seasoning.
Serve garnished with cream and fresh basil. Serves 4 as a main, or 6-8 as an entrée.
*Tip: you can do this quickly by filling a freezer bag with icy water and immersing it in the soup.