Wild mushrooms are expensive, but when reconstituted, the dried porcini have an intense flavour, so only a small quantity is needed.
Leeks - 2, thinly sliced
Shallots - 2, roughly chopped
Garlic clove - 1, roughly chopped
Fresh wild mushrooms - 8 ounces
Dried thyme - 1/2 tsp
Heavy cream - 2/3 cream
Freshly ground black pepper
Sprigs of fresh thyme to garnish
1. Put the dried porcini in a bowl, add 1 cup of warm water and let soak for 20-30 minutes. Lift the mushrooms out of the liquid and squeeze over the bowl to remove as much of the soaking liquid as possible. Strain all the liquid and reserve for use later. Finely chop the porcini.
2. Heat the oil and butter in a large saucepan until foaming. Add the sliced leeks, chopped shallots, and garlic and cook gently for about 5 minutes. stirring frequently until softened but not coloured.
3. Chop or slice the fresh mushrooms and add to the pan. Stir over medium heat for a few minutes, until they begin to soften. Pour in the stock and bring to a boil. Add the porcini, soaking liquid, dried thyme, and salt and pepper. Lower the heat, half cover the pan and simmer gently for 30 minutes, stirring occasionally.
4. Pour about three quarters of the soup into a blender or food processor and process until smooth. Return the processed soup to the soup remaining in the pan. Stir in the cream and heat through. Check the consistency and add more stock if necessary. Season with salt and pepper. Serve hot, garnished with thyme sprigs.