Thaw fish, if frozen.
Combine soy sauce, sherry, sesame seed, oil, and gingerroot.
Arrange fish in single layer in shallow dish; pour soy sauce mixture over fish.
Marinate fish for 15 minutes at room temperature, turning fish once.
Drain, reserving marinade.
Place fish in well-greased wire grill basket.
Grill over hot coals for 8 minutes.
Turn fish and brush with marinade.
Grill 7 to 9 minutes more or till fish flakes easily when tested with a fork.