Technically, persillade refers simply to the mixture of finely chopped parsley and garlic (the Italian gremolata is the same mixture plus chopped lemon zest). Simple persillade is a delicious light topping for almost anything: spread on a baguette, use as a garnish on grilled fish or chicken, etc.
For a more elaborate condiment, we like making full-fledged parsley pesto. If you use an entire bunch of parsley, add one to three cloves garlic, about ¼ to ½ cup roasted walnuts, about ¼ to ½ cup grated Parmesan cheese, salt to taste and about ½ cup extra-virgin olive oil. You can blend the ingredients (minus the oil) in a food processor and then pour the oil in last (processing just slightly further to blend). Alice Waters recommends using a mortar and pestle. We own neither, so we favor the rough chopped pesto that results from hand mixing knife-minced ingredients. Either way, if the ingredients are quality, the results will be delicious.
