Place pita bread rounds on ungreased cookie sheet, outer surface up. Broil 3 to 4 inches from heat for 2 to 3 minutes or until lightly browned, turning once.
Brush bread rounds evenly with oil. Sprinkle evenly with Parmesan cheese. Broil an additional 1 to 2 minutes or until lightly browned and toasted.
Cut bread rounds into 1 1/2x1/2-inch strips. Cool 5 minutes or until completely cooled.
Meanwhile, in very large bowl, combine salad greens, tomatoes, cucumber, onion rings, olives and feta cheese; toss gently.
Just before serving, pour dressing over salad. Add pita bread strips; toss gently.