Step 1) In a medium size bowl, add the dry rub ingredients mix well. Drizzle the corn oil over the entire flank steak, sprinkle with the dry rub mix.
Step 2) Preheat grill and lightly brush with oil. Grill steak over medium-high heat for about 4 minutes per side, or to desired doneness. Transfer meat to a cutting board; let rest while preparing the sauce.
Step 3) Combine all sauce ingredients in blender or food processor. Pulse until mixture is finely minced. Slice steak across the grain and place on serving plate. Drizzle with Chimichurri Sauce.