1. Preheat grill to medium-high heat.
2. Bring a small pot of water to a boil. Add peas; cook 5 minutes or until crisp-tender. Drain and rinse with cold water; drain.
3. Split pita into 2 rounds. Arrange the pita rounds on a grill rack coated with cooking spray, and grill for 1 minute on each side or until toasted. Remove from grill, and cool. Break pita into 1-inch pieces.
4. Combine 1 tablespoon olive oil, 1 teaspoon lemon rind, salt, and 1/4 teaspoon black pepper in a large bowl. Add shrimp; toss to coat. Thread the shrimp onto 4 (12-inch) skewers. Arrange skewers on grill rack coated with cooking spray; grill 2 minutes on each side or until done.
5. Combine remaining 2 tablespoons oil, remaining 1/2 teaspoon lemon rind, remaining 1/4 teaspoon pepper, vinegar, juice, and garlic in a large bowl. Add peas, onion, mint, and spinach; toss to coat. Arrange about 2 cups salad on each of 4 plates; divide pita and shrimp evenly among salads. Sprinkle each serving with about 1 tablespoon cheese.