2 lb. Skirt Steak
3/4 cup plus 2 tbsp. Extra Virgin Olive Oil, divided
2 1/2 tsp. Kosher Salt, divided
2 tsp. freshly ground Black Pepper, divided
1/4 cup finely chopped Red Onion
2 large Garlic Cloves, minced
3/4 cup Red Wine Vinegar
1/2 cup chopped fresh Parsley
Place a 12-inch cast-iron skillet over medium-high heat 2-3 minutes or until hot. Coat steak with 2 tbsp. oil and season both sides of steak with 1 1/2 tsp. salt and 1 tsp. pepper. Cook steak in hot skillet 3-4 minutes on each side or until a meat thermometer inserted into thickest portion registers 130 degrees (medium rare). Transfer steak to a cutting board, and cover loosely with aluminum foil; let stand 5 minutes.
Make chimichurri by stirring together onion, garlic, remaining 1 tsp. sale, and remaining 1 tsp. pepper in a small bowl. Stir in vinegar; let stand 5 minutes. Stir in parsley. Add remaining 3/4 cup oil in a slow, steady stream, whisking constantly until smooth.
Cut steak diagonally across grain into 1/4-inch-thick slices, and place on a serving platter. Pour chimichurri over sliced steak, and serve immediately.