The bread I use is a whole wheat baguette from Shadeau Breads. I cut off 1/3 and slit it into a hoagie bun. I get my fish from the two places at Findlay Market that sell fish, neither of which I can remember the name of even though I've been there four score and seven times. Remember to smell fish before you buy it. If it smells fishy, buy more.
Heat up about 1 Tbsp oil in a pan (or even better, an iron skillet like the one I bought dirt-cheap at an antique store in rural Kentucky) on medium-high. Coat the fillet in equal parts flour ("all-purpose," if you want to be technical) and cornmeal. You can dip it in milk or buttermilk first, but I just sneeze on it and rub the mucus around.
Fry the fish, about 4 minutes per side. Add salt & pepper to the face-up side, and then again after you flip it. Remember, you're pan-frying, not deep-frying. The point is to be MORE healthy than a 3-way.
While that's going on, put a couple of spoons of mayo in a bowl, add some curry powder, salt & pepper, and some lemon juice. Don't add too much because it will become too soupy and lemony. Just a teaspoon, if you're the measuring type (I'm not; I just squeeze about half of a half-lemon). If you add too much lemon then just add more mayo. No rocket science here.
Mix it up, spread it on, add the fish, and eat it up.
The key thing is to make the curried mayonnaise. It makes all the difference.
In addition to being a healthy meal that you can have the satisfaction of making yourself, catfish is not one of the mercury-laden fishes that should be avoided by childbearers, future childbearers, children of childbearers, and pretty much anyone else that doesn't want their brain to turn to