Prepare The Chimichurri Sauce/Marinade. Finely Chop The Parsley, Garlic And Oregano (Can Do With A Food Processor), Place In A Small Bowl. Stir In The Vinegar, Oil, Salt, Pepper, And Red Pepper Flakes. Set Aside Two Thirds Of The Sauce For Serving With The Steak (Cover With Plastic Wrap And Let Sit At Room Temperature). The Remaining Third Of The Sauce Will Be For The Marinade. 2 Place Steak In A Bowl Or Large Ziplock Bag. Take About A Third Of The Prepared Chimichurri Sauce And Coat The Steak For A Marinade. Cover Completely With Plastic Wrap Or Remove Air From Ziplock Bag And Secure Close. Let Steak Marinate For Several Hours. Remove Steak From Refrigerator 2 Hours Before Cooking So That It Gets Close To Room Temperature Before Cooking. Right Before Cooking, Wipe Off Marinade From Steak And Sprinkle Steak Generously With Salt And Pepper. 3A Grilling Instructions Prepare Grill So That One Side Has High, Direct Heat And Another Side Has Indirect Heat. Brush Grill Grates With Vegetable Oil. Place Steak First On The Side Of The Grill With High, Direct Heat, So That It Sears. Grill For A Minute Or Two On Each Side, Enough To Brown The Meat. Then Transfer The Steak To The Indirect Heat Side Of The Grill. Cover The Grill, Try To Maintain A Grill Temperature Of 350