Marinated Flank Steak

Serves 6Ingredients1 small red onion, quartered1⁄3 cup balsamic vinegar1⁄4 cup capers, drained2 tablespoons chopped fresh oregano3 cloves garlic, minced1 1⁄2 pounds flank steak1⁄4 teaspoon salt1⁄4 teaspoon coarsely ground black pepperInstructionsSliver one-quarter of the onion and set aside. Chop the rest of the onion. Mix it in a bowl withthe vinegar, capers, oregano,