Season the steak with salt and pepper, and let it sit on the counter for 30 minutes.
In a food processor, combine the vinegar, lemon juice, 1/4 cup olive oil, red onion, paprika, and garlic. Purée into a thick red paste.
Add the parsley, oregano, and a pinch of salt and pepper. Purée until it's a nice green paste.
Preheat grill or broiler. Coat steak with remaining 1 tablespoon olive oil. Cook 2 to 3 minutes per side for like medium-rare. When done, remove and set aside for five minutes.
Cut against the grain, and pour chimichurri atop. Eat!