Thaw fish, if frozen. Rinse fish; pat dry with paper towels. Place fish in a resealable plastic bag set in a shallow dish. For marinade, in a small bowl stir together oil, lemon juice, cumin seeds, pepper, and garlic. Pour over fish; seal bag and turn to coat fish. Marinate in the refrigerator for 30 to 60 minutes, turning fish once. Drain fish, reserving marinade.
Lightly grease or coat with nonstick spray an unheated grill rack. For a charcoal grill, grill fish on the greased rack of an uncovered grill directly over medium coals for 8 to 12 minutes, or until fish begins to flake when tested with a fork and center of fish is still slightly pink, gently turning and brushing once with remaining marinade halfway through grilling. Discard any remaining marinade. (For a gas grill, preheat grill. Reduce heat to medium. Place fish on greased grill rack over heat. Cover and grill as above.) Serve fish with sauce. Makes 4 steaks.
Cumin Tartar Sauce
Finely chop any large fruit pieces in chutney. In a small bowl combine chutney, mayonnaise or salad dressing, Dijon-style mustard, lemon juice, and cumin seeds, toasted. Cover and chill until serving time.