There are a lot of good cat recipes out there, but here's a very easy way to prepare bullheads. No one I've ever spoken with about it had ever tried it before.
It's the way my dad fixed them going back 40 years. He was a bullhead fishing freak.
Knock off the heads and gut, skin and fin. Soak them in fairly salty water for a few hours (overnight is good, but keep refridgerated).
Then just put them on the BBQ grill until they're flakey--charcoal is better than propane, but everyone knows that.
Some in the family liked them with BBQ sauce or a mild honey glaze. For me, just hit them with a little salt and pepper. Eat 'em like corn-on-the-cob and stack up the bones.