Pour 1/4 cup Wish-Bone® Italian Dressing over steak in large, shallow nonaluminum baking dish or plastic bag; turn to coat. Pour 1/4 cup Dressing over red peppers and onion in another large, shallow nonaluminum baking dish or plastic bag. Cover, or close bags and marinate in refrigerator 3 to 24 hours.
Remove steak and vegetables from marinades, discarding marinades. Grill or broil steak and vegetables, turning once and brushing frequently with remaining 1/2 cup Dressing, until steak is desired doneness and vegetables are crisp-tender.
Lightly grill tortillas, turning once and brushing with additional Dressing, if desired. Tear tortillas into bite-size pieces.
To serve, thinly slice steak and vegetables. Arrange lettuce on serving platter, then top with steak, vegetables, tortillas and lime. Serve, if desired, with additional Dressing.