Ingredients

• 3/4 cup fine-quality fermented soy sauce*
• 1/2 cup dry red wine
• 1/4 cup fresh lemon juice
• 1/3 cup fresh orange juice
• 3 tablespoons olive oil
• 1 bunch scallions, cut into 3-inch lengths
• 5 garlic cloves, smashed and peeled
• 1/2 teaspoon white pepper
• Pinch of cayenne
• 2 1/2 to 3 lb top-round London broil (1 to 1 1/2 inches thick)
• 1 cup mayonnaise
• Special equipment: an instant-read thermometer
• Accompaniment: toasted or grilled country bread

Instructions

1. Combine soy sauce, red wine, juices, 2 tablespoons oil, scallions, garlic, white pepper, and cayenne in a 1-quart heavy-duty sealable plastic bag. Add steak and seal bag, pressing out air. Turn bag to coat steak, then marinate, chilled, turning bag occasionally, at least 4 hours.
2. Transfer steak to a plate and pour 2 tablespoons marinade through a fine-mesh sieve into a 1-quart heavy saucepan, discarding remainder or reserving for another use (see cooks' note, below). Bring steak to room temperature, about 30 minutes.
3. Heat remaining tablespoon oil in a 12-inch heavy skillet over moderately high heat until hot but not smoking, then cook steak, uncovered, until underside is browned, about 5 minutes. Turn steak over, then reduce heat to moderately low and cover skillet. Continue cooking until thermometer inserted horizontally 2 inches into center of steak registers 120°F, 10 to 12 minutes. Transfer to a cutting board and let stand at least 15 minutes (internal temperature of steak will rise to 130-135°F for medium-rare).
4. While steak cooks and stands, bring marinade in saucepan to a boil, then pour into a bowl and cool completely. Whisk in mayonnaise until combined well and chill, covered, until ready to serve.
5. Holding knife at a 45-degree angle, cut steak across the grain into very thin slices and transfer to a platter, then drizzle with any juices accumulated on cutting board. Serve at room temperature or slightly chilled, with mayonnaise.