Using a blender or food processor, add the cilantro, parsley, red wine vinegar, garlic, salt, cumin, and crushed red pepper. Mix for 20 seconds, stopping to scrape the sides as needed.
With the machine running on low speed, slowly add the olive oil in a thin, steady stream. Cover and process on medium-high speed until smooth and slightly thickened, about 60-90 seconds. Season with salt and pepper to taste.