Put the parsley and garlic in a small glass bowl.
Add the olive oil, vinegar, salt, pepper, and red pepper flakes, and mix until well blended.
Serve over any grilled meat you'd like. It's especially tasty on grilled steak and chicken.
Makes over 1 cup of Chimichurri Sauce.
You can store chimichurri sauce in the fridge in a glass container for at least a week. If you won't be able to use it in that amount of time, freeze it in ice cube trays and use as needed.