What other food can I give cat with crystal/urinary problems that’s not prescription?

Last year my sweet boy had a partial urinary blockage. After an ER stay he was better and started on Hills urinary care c/d diet, wet & dry and it has been working wonderfully. I also give him urinary treats.

Is there any other food I can give him? Like chicken? Any other meat products safe for cats with urinary problems? Any other cans, that aren’t prescription, safe for him?

I feel so bad that he’s stuck on this diet now (not bad that he doesn’t have crystals anymore but bad that he’s stuck eating the same cans & dry food everyday).

I just want my boy to get some more flavor in his life lol, thank you in advance!