My cats go crazy over scrambled eggs and tuna, and the vet says that is fine if fed that occassionally. Pretty much any meat prepared fresh (except pork or ham) is ok as long as it isn't heavily seasoned so steak, fish, chicken is all ok for a treat. We got our newest kitten to start eating food and stop taking the bottle by letting him lick mashed potatoes off our fingers.
Gizmo will eat ANYTHING though. It doesn't matter. Chips and dip, popcorn, carrots, if it's on our plate, he wants it. One night when our backs were turned, he stole a hot wing from DH's plate. Not mild, not medium, but suicide hot! And ate almost the whole thing. He wasn't real happy the next day trying to get that out
but the vet said he would be fine. So, add hot wings to the list of what not to feed your cat.