That sounds delicious.

Here is what I do with the leftover filets when sauteed with the flour and
egg recipe above.  We deliberately plan for extras to get a cold fish
appetizer for the next day.   This is actually Ida's recipe which she taught
me years ago when she was such a great cook.

In the same pan where the fish filets were sauteed, add a rather large
amount of cut up onion.   Saute the onions in the olive oil till they begins
to become tender.   Add about 1/2 cup of Marsala wine (cheap stuff only, you
will ruin it with good Marsala) and about 1 cup of regular ketchup.    Cook
onions and ketchup and wine together and season it with a bit of Kosher salt
and some coarsely ground pepper.  It should be a bit thinner than regular
ketchup, so add water if needed to get the right texture.

Now layer a pan with ketchup/onion sauce, fish filets, more sauce, more
filets, till you have a couple of layers, and top it with the last of the
sauce and onions.

Refrigerate overnight, which allows the fish to marinate somewhat.

Serve cold.

This stuff is so delicious you cannot imagine how good it is.   I
deliberately buy way more fish filets than I need just to be able to make
this for the next day.   It will keep several days too.   It is excellent to
bring as a covered dish to parties as well.