1Brush grill rack with canola or soybean oil. Heat coals or gas grill for direct heat.
2Spread nuts in shallow microwavable bowl or pie plate. Microwave uncovered on High 30 seconds to 1 minute, stirring once or twice, until light brown; cool. Mix hazelnuts and remaining hazelnut butter ingredients in small bowl; set aside.
3If fish fillets are large, cut into 4 serving pieces. Sprinkle both sides of fish with salt and pepper.
4Cover and grill fish 4 to 6 inches from medium heat 4 minutes. Turn; spread about 1 tablespoon hazelnut butter over each fillet. Cover and grill 4 to 6 minutes longer or until fish flakes easily with fork.