Ingredients
4  6-ounce fresh or frozen halibut steaks, cut 1 inch thick
2  tablespoons margarine or butter
2  tablespoons lemon juice
1  tablespoon Dijon-style mustard
2  teaspoons snipped fresh basil or 1/2 teaspoon dried basil, crushed

Directions
1. Thaw fish, if frozen. 

2. In small saucepan heat margarine or butter, lemon juice, mustard, and basil over low heat until melted. Brush both sides of steaks with mustard mixture. 

3. Grill fish steaks on the greased rack of an uncovered grill directly over medium coals for 8 to 12 minutes or just until fish begins to flake easily when tested with a fork, turning once and brushing occasionally with mustard mixture. Makes 4 servings.
 
To grill by indirect heat: Arrange preheated coals around a drip pan in a covered grill. Test for medium heat above pan. Place fish on the greased grill rack over drip pan. Cover and grill for 8 to 12 minutes or just until fish begins to flake easily when tested with a fork, turning once and brushing occasionally with mustard mixture.

Source:  Better Homes & Gardens