Hi, my cat has a sensitive stomach (although it is getting tougher now and I can feed him a few different things!)

normal chicken is fine

plus these sensitive wet foods from zooplus -

Kattovit Gastro 6x 175g: Great Deals on Kattovit Cat Food at zooplus

Integra Canned Cat Food at zooplus

Animonda vom Feinsten for Neutered Cats 6 x 100 g: Great Deals on Animonda Cat Food at zooplus

Mainly the idea is to have a single source protein cat food so grau (which has rice in small quantities too which can help sensitive stomachs) and applaws/feline porta chicken should be ok too.

He may be stressed from being rehomed so his stomach might settle down a bit more in time. My cat has liked all the ones I linked to above but he has gone off them too. I found the kattovit seemd to result in overly dried poos once his runs had stopped so then stuck to integra and animonda. He loved the animonda turkey and (very tiny amounts of salami) and ate only that for a few months. Then just after I'd ordered another load from zooplus he told me he'd gone off it now

I've tried other stuff now he's got a bit bored with those and he does seem to manage eg hilife which he couldn't before. (Although I stuck to the poultry varieties rather than the more mixed fish ones but he's gone off that now anyway!) I still look out for mainly one source of protein now with perhaps a small amount of meat of another animal. I wouldn't risk eg butchers classic although I think that's an alright food for cats in general without sensitive tummies to have sometimes.