This is a quick dish that’s exciting to make in the all-too-short autumn porcini season, but because fresh porcini are available so briefly and are expensive, we have used dried ones so that you can cook it all year round.
Bring the milk to the boil in a small saucepan, then remove from the heat, add the dried porcini and leave them to soak for 30 minutes. Using a stick blender or liquidizer, blend the milk and porcini until you have a smooth paste. Mix in the crème fraîche and set it aside.
Bring a large pan of salted water to the boil and add the linguine to it, stirring freque