Blend together the parsley, red wine vinegar, garlic, oregano, red pepper flakes, and olive oil in a food processor or blender, scraping down the sides with a spatula as necessary. Do not over-process the mixture. You want the sauce to have body and texture. Then season with salt and pepper, to taste. (If you don't have either of these appliances, you can chop the herbs and vegetables by hand, transfer them to a mixing bowl. Then whisk in the olive oil, vinegar, and red pepper flakes and season with salt and pepper, to taste.) Enjoy!