Help me find this book?

[Dallerup]

I can hardly remember anything but hoping it rings some bells for someone.

It's set in London (present day I think but almost certainly no earlier than the 70's at a push) and the story is told through the different characters perspectives. An Iranian restaurant owner and a much younger English waitress. He's married but there's an attraction and she ends up being his second wife even though neither of them are fully comfortable with the idea of polygamy. Fairly sure his wife and her mum (who she lives with on a high rise council estate) are completely supportive and actually help them through their moral struggles over the relationship.

I'm not convinced I've got all of the details correct (definitely Iranian because he reminisces and discusses Persia in some detail) so throw some suggestions even if they don't fit perfectly. I definitely read it over 5 years ago although could be much older than that and I'm sure I borrowed it from my Mum (who looked at me like I was speaking in tongues when I asked her about it) so possible it was a Richard and Judy book club type read

The English Harem, can't remember the author but you could look it up. They did a TV version of it too, although the lead was way more handsome than the book version which kind of killed the story for me.

Amazing! Yes that's it. Looks like there's much more to it than I remember so rereading it should be good. Art Malik in the TV version, I've always quite liked him so maybe worth a watch after rereading it. Thank you!