Grilled Beef and Avocado Pitas

Score both sides of steak in a diamond pattern by making shallow diagonal cuts at 1-inch intervals. Place steak in a resealable plastic bag set in a shallow dish.

In a screw-top jar, combine salad dressing, lime peel, lime juice and cilantro. Cover and shake well. Pour half of the salad dressing mixture into a small bowl and add onion; cover and chill until serving time. Pour the remaining salad dressing mixture in the jar over steak in bag. Seal bag; turn to coat steak. Marinate in the refrigerator for 24 hours, turning bag occasionally.

Drain beef, discarding marinade. Sprinkle with salt and black pepper. For a charcoal or gas grill, grill steak on the rack of a covered grill directly over medium heat for 17 to 21 minutes for medium doneness (160 degrees F), turning once halfway through grilling time.

To serve, thinly slice beef across grain. In a large bowl toss together beef, salad greens, sweet pepper, avocado and the dressing-onion mixture. Divide beef mixture among pita halves.