The key for how to make sirloin steak recipes that are supremely tender and juicy: A sirloin steak marinade with plenty of acid (here, lemon juice).
Trim fat from meat. Place meat in plastic bag set in shallow dish. For marinade, combine remaining ingredients; pour over meat. Close bag. Marinate meat for 2 to 6 hours on refrigerator, tuning the bag occasionally.
Remove meat from marinade; pat dry. Grill on rack of uncovered grill directly over medium coals, turning over halfway through grilling time. (Allow 16 to 18 minutes for medium-rare or 18 to 22 minutes for medium doneness.) Brush occasionally with marinade up to the last 5 minutes of cooking. To serve, thinly slice across grain. Makes 8 to 10 servings.