Soak capers in fresh water for ½ hour. Rinse well.
freeze the yellow tail tuna loin until it is partially frozen, approximately 2 hours. Cut into thin slices and place on individual plates. Keep refrigerated.
mix together lemon, oil and a little salt and pepper.
season tuna with capers, part of the lemon dressing, basil, salt and pepper. On the side mix the salad with the tomatoes and the remaining dressing. Place a little salad at the center of each plate before serving.