In a small shallow bowl blend the mayo and mustard. In another medium bowl mix the bread crumbs, shredded coconut, chopped mixed nuts, sugar, salt and cayenne pepper. I used a combination of macadamia nuts and pecans. But be creative, I think any combo will work well.
Dip the fish (I used wild catfish) in the mayo/mustard mixture and coat it well. Then coat it well with the bread-crumb-coconut mixture and put in the prepared pan. I lined mine with parchment, but it's not necessary if you grease the pan.
Bake 20 minutes or until golden on the outside. The fish should be flaky and tender inside.