PREPARATION:
- Combine oil, vinegar, garlic, rosemary and pepper in food processor or blender; process until rosemary is finely minced. Place 1/4 cup dressing in medium bowl. Add tuna; turn to coat. Cover and refrigerate 1 hour. Pour remaining dressing into jar with tight-fitting lid. Set aside.
- Cook potatoes in boiling water 6 minutes or until just tender. Transfer to medium bowl; add onion. Shake dressing and pour about 2 tablespoons over potato mixture; toss gently to coat.
- Add green beans to simmering water; cook 3 minutes or until crisp-tender. Drain and rinse under cold water.
- Thread potatoes and onion onto skewers. Thread tuna onto separate skewers. Grill vegetables over medium-hot coals about 10 minutes or until well browned. Grill tuna 6 to 8 minutes or until fish flakes when tested with fork.
- Toss lettuce with 1/4 cup dressing; transfer to large platter. Toss green beans with remaining dressing; arrange over lettuce. Remove tuna, potatoes and onion from skewers; place on salad. Garnish with tomato, olives, egg whites and capers.
