1. Combine first 4 ingredients in a large heavy-duty zip-top plastic bag; add pork, turning to coat. Seal bag, and marinate in refrigerator 30 minutes, turning bag occasionally.
2. Place 1/2 cup cucumber, dill, and yogurt in a food processor; process 10 seconds or until smooth, scraping sides of processor bowl once.
3. Prepare grill.
4. Remove pork from bag; discard marinade. Place on a grill rack coated with cooking spray. Cover and grill 25 minutes or until a meat thermometer registers 155°, turning occasionally. Remove from grill; let stand 10 minutes or until thermometer registers 160°. Cut into thin slices.
5. Divide lettuce among 4 plates; top evenly with remaining cucumber, onion, and next 6 ingredients. Top evenly with pork. Top each with 6 tablespoons dressing.
carbo rating: 13