On 4 large buttered squares of heavy-duty aluminum foil, place equal amounts of fish.
In small saucepan, melt margarine; add lemnon juice, parsley, dill weed, salt and pepper.
Pour equal amounts over fish.
Sprinkle with paprika; top with onion slices.
Wrap foil securely around fish, leaving space for fish to expand.
Grill 5 to 7 minutes on each side or until fish flakes with fork. Refrigerate leftovers.