In shallow dish, combine lime rind and juice, oil, mustard and pepper; add fish, turning to coat. Cover and marinate at room temperature for 30 minutes, turning occasionally.
Reserving marinade, remove fish; sprinkle with sesame seed. Place on greased grill directly over medium heat. Add soaked wood chips. Cover and cook, turning and basting with marinade halfway through, for 16-20 minutes or until fish flakes easily when tested with fork.
1 teaspoon grated lime rind
1/4 cup lime juice
1 tablespoon vegetable oil
1 teaspoon Dijon mustard
1 pinch pepper
4 salmon steaks, 1-inch thick 1-1/2 lb.
1/3 cup toasted sesame seed [opt.]