This mixture of finely chopped olives makes a marvelous spread for toasted croutons, hot pasta, and grilled vegetables, fish, and meats. This recipe uses a mortar and pestle, but a food processor can be used, although the texture will be more homogeneous and much of the rustic, rough-hewn quality of the sauce will be lost. Tapenade recipes always contain capers—tapéno means “caper” in the Provençal dialect—but the dried currants, which add a note of sweetness that relieves the saltiness of the mixture, are not traditional.