To the container of a blender or food processor, add the parsley, oregano, cilantro, onion, and garlic and pulse to mince.
Add the red pepper flakes, olive oil, vinegar, and lemon juice and pulse 2-3 times to mix.
Season with kosher salt and add more to taste.
Or, finely mince all of the ingredients with a sharp knife, then whisk with the olive oil, vinegar, and lemon juice in a bowl or shake in a covered glass jar.
