Heat oven to 400 degrees F. Mix all dry ingredients in a small bowl. Stir in harissa, garlic and olive oil.
Rinse any ice glaze from frozen Alaska Halibut under cold water; pat dry with paper towel. Place halibut portions in spray-coated baking dish. Spoon and spread spice mixture over top of halibut. Cover dish with foil; seal. Roast 18 to 25 minutes for frozen halibut or 10 to 15 minutes for fresh/thawed fish. Cook just until fish is opaque throughout.
Variation: Remove foil during last 10 minutes of cooking, until lightly browned.