Process 3/4 cup Hellmann's® or Best Foods® Light Mayonnaise, chipotle peppers and lime juice in food processor or blender until smooth. Arrange steak in baking dish. Rub both sides with mayonnaise mixture. Cover and marinate in refrigerator 30 minutes.
Meanwhile, combine cilantro, garlic salt and remaining 3/4 cup Mayonnaise in small bowl; cover and chill.
Grill steak, turning once, 8 minutes or until desired doneness. Slice steak and serve with cilantro sauce.