This easy sauce comes together in a snap in your blender and is a great accompaniment to any cut of lamb or beef. Got extras? Use it as a flavorful marinade! Leftover sauce can be covered and refrigerated for 1 day, then returned to room temperature before serving.
In a blender, combine the herbs, jalapeño, red pepper flakes, garlic, half of the oil, 3/4 teaspoon salt, and 1/4 teaspoon pepper. Purée, stopping to scrape down the sides of the container if necessary. Gradually add the rest of the oil.
Add the vinegar, blend for 1 second and then add a little water if you’d like the sauce to be thinner. Taste, add salt and pepper if desired, and serve right away.