I would bet at least steamed/boiled in a little water till tender.
I doubt the Discus would peck at it in the substrate but light eat tiny bits dropped in one or 2 at a time per fish.
A Pleco would gnaw at it if they wanted to eat it and could be pretty raw/on the raw side.
What other tropical fish are in there?
I would peel, cube into 1/2 to 1 inch pieces and cook til firm but tender when pushing in a fork. Then cut in mouth sized bits for Discus. They may or may not like it much, they may need a few sample feedings to get to like it.
Discus are big meat eaters.
You could refrigerate, and or freeze it for future feedings, defrost first before feeding.