In small bowl, stir together oil, chili powder, salt, pepper and garlic; brush over steak and let stand for 15 minutes.
Option 1 - Grill Steaks: Place steak on greased grill over medium-high heat; close lid and grill, turning once, until medium-rare (or until desired doneness), about 8 minutes. Transfer to cutting board and tent with foil; let stand for 5 minutes before thinly slicing across the grain.
Option 2 - Broil Steaks: Preheat oven broiler to 475F/ 250C. Place marinated steaks on broiler pan and cook, turning once to cook both sides equally. Cook for 3-4 minutes on both sides for medium rare steaks. Transfer to cutting board and tent with foil; let stand for 5 minutes before thinly slicing across the grain.
To make salad: Meanwhile, in large bowl, combine cooked barley, corn, tomatoes, coriander, onion, oil, lime juice, cumin and salt; toss to combine.
Divide lettuce among plates; top with salad. Arrange steak over top.