First, add the cilantro, parsley, garlic, red pepper flakes, and salt to a food processor. Pulse the mixture until it's finely chopped.
Next, with the food processor running, slowly drizzle in the olive oil and red wine vinegar. Stop to scrape down the sides of the food processor as needed.
Once all of the ingredients are fully combined and the mixture is smooth and creamy, transfer the cilantro chimichurri to a serving bowl.