There is a very good parmesan-crusted cod recipe in Abigail Dodge's Around the World Cookbook. The cookbook is aimed at kids, so it is good if you are a novice-- and if you are not a novice, don't be put off, I cook from it all the time. For the fish, the filets are laid in the pan, spread with a thin coating dijon mustard, then covered with a combination of bread crumbs, fresh grated parmesan, and melted butter. Then the whole thing is baked until the fish is cooked and the crumbs are browned.
Does this sound like what your wife likes? If you can't find the book, I can provide you with some more specifics on quantities, times, and temperatures. If this recipe isn't it, then some more description would help-- is the fish baked or fried?
Good luck and happy cooking!
Cheers, Jen