In a medium bowl, whisk together vinegar,
tablespoons oil, oregano, lemon juice, and garlic. Place steak in a large resealable plastic bag; add marinade, and seal bag. Refrigerate for 2 hours.
Preheat oven to 425°.
In a small bowl, stir together salt and pepper. Rub steak with salt-and-pepper mixture.
In a large ovenproof skillet, heat remaining 1 tablespoon oil over medium-high heat. Add steak; cook for 4 minutes per side. Transfer to oven.
Bake until a meat thermometer inserted in center registers 120°, 10 to 15 minutes.