Remove gills and clean.  Wash and pat dry inside and out.  Lay fish
 on heavy foil.  Stuff innards with slices of potatoes, onions, and
 lemon (these will absorb the oil in the fish and will be discarded.
 Pour a cup (or so, depending on how large the fish is) of Chablis
 over the fish and close the foil tightly.  Bake at 350 degrees F.
 (or over a grill) until it just begins to flake.