1.Make grape and lychee salad. Place ingredients in large bowl; toss gently to combine.Season to taste.
2.Dry-fry rice in medium frying pan until toasted lightly.
3.Blend or process rice and white sesame seeds about 2 minutes or until powdery. Combine powder in small bowl with black sesame seeds.
4.Cook tuna on heated oiled barbecue (or grill or grill pan) about 8 minutes or until browned all over. Remove from barbecue; cover, stand 10 minutes.
5.Coat tuna with honey mustard sauce. Place tuna on tray; coat with sesame mixture.
6.Slice tuna; serve with salad.