Russula xerampolina is one of the few mushrooms with a firm enough texture and rich enough flavor to compliment green olives. The fishy overtones in the mushroom add an appropriate foil to the salt and garlic. You can use this as an accent for Spanish tapas, on crackers with cheese, mixed into a loaf of bread, or any time you want to add something strong, deep and savory.
Sauté the mushrooms, oil and garlic together for about 5 minutes, stirring. Remove from heat. Chop the olives and herbs to a medium consistency, and stir into the cooked mushrooms, along with the vinegar and wine. Now squeeze the mixture very tightly into a 10 oz. jar, leaving as few air pockets as possible. Cover and let sit in the refridgerator for several days before using. The flavors will mellow and merge with time.