Combine the garlic with the basil and parsley leaves, the bread slices, and the vinegar in the bowl of a food processor. Puree the herb/bread mixture for about 1 minute, scraping down the sides of the food processor with a rubber spatula every 10 or 15 seconds. Add the mustard, capers and cornichons and chop for about a minute more, until the mixture is granular but smooth. Put the mixture in a bowl, work in the olive oil with a wooden spoon, and stir in the salt and pepper to taste.
Recipe courtesy of James Peterson