Combine Becel® Buttery Taste margarine, shallots, tarragon, parsley, mustard, lemon juice and garlic in small bowl. Store covered in refrigerator until ready to use.
Grill or broil halibut, turning once, until fish flakes with a fork, about 10 minutes. Remove halibut to serving platter, the spread about 1 Tbsp. (15 mL) Becel mixture over each fillet to create a sauce.