Scale and clean fish removing head. A one pound fish can be cooked whole and serves one person. Cut larger fish into portions. Place a slice of bacon on a square of extra strong foil. Place fish on bacon, add sliced onion, a slice of lemon, salt and pepper and paprika and a pat of butter. Bring foil up over fish. Seal tight over top with double fold, seal ends. Place packets on grill 4 inches over hot grey coals. Cook about 20 minutes turning once.