To prepare spice mixture, combine first 5 ingredients in a small bowl.
To prepare glaze, combine rind and next 8 ingredients (rind through cinnamon) in a saucepan. Bring to a boil. Reduce heat, and simmer 10 minutes. Strain through a sieve; discard solids.
Rub the fillets with spice mixture. Cover; refrigerate 10 minutes. Place, skin sides down, on a grill rack coated with cooking spray. Grill 16 minutes, covered, or until fish flakes easily when tested with a fork, basting occasionally with glaze. Remove skin; discard. Arrange fillets on a platter; sprinkle with sliced onions and sesame seeds.