Mushroom soup

Ingrediënten

• 10g dried shiitake mushrooms
• 10g dried porcini mushrooms
• 1.5kg vegetable stock (p.44)
• 160g unsalted butter
• 2 onions, peeled and finely sliced
• 1 small potato, peeled and finely sliced
• 2 leeks, white part only, cleaned and finely sliced
• 800g button mushrooms, finely sliced
• 50g dry white vermouth
• 80g double cream
• 40g semi-skimmed milk
• Salt and black pepper