1 cup packed parsley leaves (about 1 ounce), washed and dried
1 tablespoon extra-virgin olive oil
1 small clove garlic, peeled
Salt and freshly ground black pepper to taste
1/3 cup sherry vinegar or other good, fairly mild vinegar
Place the parsley in a food processor, along with the oil, garlic, a healthy pinch of salt and about 1/4 teaspoon of pepper. With the machine on, drizzle the vinegar through the feed tube until the parsley is pureed.
Add a tablespoon of water and pulse the machine on and off a couple of times; taste. The mixture should taste sharp, but not overpoweringly so. If it seems too sharp, add a little more water; the texture will be quite loose, something like thick orange juice. Taste and add more salt and pepper if necessary. Pass the sauce at the table. Spoon it over grilled, broiled or roasted steaks, pork or chicken.
Although many sources insist that flat-leaf parsley is better than the curly-leaf variety, blind tastings have not borne out that myth; what matters more is freshness, because limp parsley has no flavor. Also, parsley is sandy, so wash it well. In the quantity given here, it’s worth using a salad spinner afterward to make sure it is thoroughly dry.