- 1/2 cup soy sauce
- 1/2 cup dry white wine
- 1/2 onion, chopped
- 3 tablespoons chopped fresh rosemary
- 2 tablespoons olive oil
- 2 garlic cloves, chopped
- 1 2-pound flank steak, trimmed
- 1/2 cup sour cream
- 1 tablespoon plus 1 teaspoon prepared horseradish
- 2 green onions, chopped
- Romaine lettuce leaves
- FOR STEAK: Combine first 6 ingredients in glass baking dish. Add steak and turn to coat. Cover and marinate overnight, turning occasionally.
- FOR SAUCE: Mix first 3 ingredients in small bowl. Season with generous amount of pepper. (Can be prepared 1 day ahead. Cover and refrigerate.)
- Prepare barbecue (high heat). Drain steak. Pour marinade into small saucepan and boil 1 minute. Season steak with generous amount of pepper. Grill to desired doneness, basting occasionally with marinade, about 6 minutes per side for rare. Transfer steak to plate and let stand at least 15 minutes. (Can be prepared up to 2 hours ahead.) Cut steak across grain into thin diagonal slices. Line platter with romaine leaves. Top with steak. Serve warm or at room temperature with horseradish sauce.