Raw, or cooked? Raw, don't cook it. When you begin feeding your raw this type of food, don't cook it then either.
Any fish? Get plain ole unseasoned cod from the grocery store.
Wouldn't such a massive ammonia spike destroy any bb? No, that is the bacteria's job to break it down. If you were to move some media from your existing tank over to this one, it would simply multiply due to the increased amount of ammonia. BB can be thought of as supply and demand. As supply of ammonia goes up, demand for BB increases, additional BB develop to handle the increased load.
My preferred way to feed BB in a fishless tank is dosing with pure ammonia, super clean, no rotting fish, etc. but either way will work fine.