Place shrimp on skewers. Brush with olive oil and season with salt and pepper. Grill over medium-high heat about 2 minutes per side until pink and opaque. Remove from skewers and set aside.
Cut heads of lettuce lengthwise. Brush with olive oil and grill over medium-high heat cut side down 2-3 minutes total, turning occasionally. Remove and set aside.
Grill the pita bread turning occasionally until crisp. Crumble into bite sized pieces. Arrange grilled lettuce on individual plates. Top with shrimp, pita, garbanzo beans, tomato, cucumber, onion and cheese. Drizzle dressing over salad and serve immediately.