Combine all dry rub ingredients in a mixing bowl.

Place all chimichurri ingredients in a blender. Mix until almost smooth.

Remove the steak from the refrigerator a half hour before cooking. Using a sharp knife, slice shallow cuts through the meat. The cuts should be at an angle, in the direction of the grain of the meat as the knife tip is going in. The cuts should be about an inch apart from each other. Turn the steak over and repeat the cuts on the other side.

Preheat the grill to medium high heat and rub the steak on both sides with the rub.

Place the steak on the grill and cook for 5-6 minutes until meat is seared, flip and cook an additional 5-6 minutes until desired doneness.

Place a piece of foil on grill and add onions, and a drizzle of olive when steak is almost done.

When your steak is done remove and let rest. Continue cooking onions until lightly brown and soft.