Combine all of the ingredients in the bowl of an electric mixer fitted with the dough hook. Beat at medium speed for about 1 minute, or until everything is well mixed. Or use a food processor, taking care not to puree the mixture or let it turn into a paste. The texture should be like finely chopped meat.
Use immediately or place in an airtight container, drizzle some of the reserved olive oil over the top, and store in the refrigerator for up to 1 week.
Yield: about 2 1/4 cups