1) For marinade, combine dressing, garlic, oregano and black pepper in a small bowl; whisk. Place steak and marinade in resealable plasticfood storage bag; turn to coat. Marinate in refrigerator 6-8 hours or overnight, turning occasionally.
2) Prepare grill for direct cooking over medium coals. For salad, quarter artichoke hearts and cut tomatoes into wedges. Slice cucumber; cut slices in half. Slice onion into thin wedges. Slice olives.
3) remove steak from marinade; discard marinade. Place steak on grid of grill. Grill, uncovered 17-21 minutes or until steak is medium rare to medium doneness, turning occasionally. Remove steak from grill. Carve steak diagonally across the grain into thin slices.
4) Arrange lettuce on large serving platter; top with steak slices, artichokes, tomatoes, cucumber, onion and olives. Top with feta cheese.