Looking after a post op cat- food etc

[HeatAndEat]

I need some help please.
My cat is having a suspicious lump cut out on Friday.
It pretty much looks like breast cancer, every single symptom fits.
She may get spayed in the same op.
We have been asked to feed her plain food, like chicken and white fish after the op.

But I'm a lifelong vegetarian so I have no clue. Can I buy a tray of roast chicken pieces and feed her that?

I've never looked at any meat products ever I assume it will be near ham and such like in the shop fridge.
Can I buy fish fingers and cut the breadcrumbs or batter or whatever the outside stuff is off and feed her the white middle?

Please be gentle with my ignorance as you can imagine the stress I'm feeling.

Thanks

I just feed my two their normal food post op. They wouldn't touch white fish or chicken. When my dear departed girl had surgery I had to pre ward the vet that she absolutely wouldn't eat while she was there. But certainly would when she got home. And she did. Head straight in the bowl.
One of mine is having a scale and polish on Monday. She'll get her normal afterwards.

Hope all goes well.