Wash and pat dry the parsley. Remove the thicker stems, and finely chop it.
Peel the garlic and cut it in half lengthwise. Remove the core (if any) then finely mince the garlic.
To a small mixing bowl or in a medium sized jar, add finely chopped parsley, minced garlic, dried oregano, salt, redpepperflakes, oliveoil, and vinegar.
Mix well with a spoon and your chimichurri is ready. For best flavor, let sit for at least 10 minutes before serving.