INSTRUCTIONS
1. Combine soy sauce, Worcestershire, scallions, 2 tablespoons sugar, garlic, mustard, vinegar, and 11/2 teaspoons pepper in bowl. Slowly whisk in oil until incorporated and sugar has dissolved. Pat steaks dry with paper towels and sprinkle all over with remaining 2 teaspoons sugar, ½ teaspoon salt, and ½ teaspoon pepper.
2. Turn all burners to high, cover, and heat grill until hot, about 15 minutes. Leave all burners on high.
3. Clean and oil cooking grate. Grill steaks (uncovered and directly over coals if using charcoal; covered if using gas) until well browned and meat registers 125 degrees for medium-rare, 2 to 4 minutes per side. Transfer steaks to 13 by 9-inch pan and poke all over with fork. Pour marinade over steaks, tent with aluminum foil, and let rest for 5 minutes. Transfer meat to carving board and slice thinly against grain. Pour marinade into serving vessel. Serve, passing marinade at table.
