Some might consider it sacriledge to combine the delicate richness of Boletus edulis with the strong sour and salty flavors below, but I don't care. The result is delicious. Although the porcini might be slightly overpowered, it adds a mysterious depth to this tapenade. I love strong flavors, and this shows how a flavor can be both strong and complex. You can use this in cooking, or on crackers or bread.
Soak the mushrooms in the water for about an hour. Move them to a sauce pan and boil until the water is mostly gone, having been evaporated and reabsorbed by the mushrooms. Place the mushrooms in a food processor with the other ingredients and chop briefly. Don't go all the way to a paste consistency, but stop when still a bit coarse. Place in a jar and store in the refridgerator.