Rinse the parsley and cilantro under cold water and pat them dry.
Remove any thick stems from the parsley and cilantro.
In a food processor, combine the parsley, cilantro, garlic, dried oregano, red pepper flakes, salt, and black pepper.
Pulse a few times until the herbs are roughly chopped.
Add olive oil, red wine vinegar, and lemon juice to the mixture.
Pulse again until the ingredients are well combined but not completely smooth.
Taste the chimichurri sauce and adjust seasoning if needed. Add more salt, pepper, or red wine vinegar as per your taste.
Transfer the sauce to a bowl or jar.
Serve immediately or cover and refrigerate for up to one week.
