london broil recipe

1 1/2 to 2 lbs flank steak or top round steak 1/4 cup soy sauce 2 tablespoons Worcestershire sauce 2 tablespoons olive oil 2 tablespoons balsamic vinegar 2 cloves garlic, minced 1 teaspoon dried oregano 1 teaspoon dried thyme 1/2 teaspoon black pepper