You will definitely see jalapeños and such on UK food packaging. I just searched the bbc website for "jalapeño" and found this page [0] which uses both spelling

You will definitely see jalapeños and such on UK food packaging. I just searched the bbc website for "jalapeño" and found this page [0] which uses both spellings (!). It also links to a page on "habañero" (sic) so yeah you can say that British familiarity with Ñ is somewhat of a mixed bag. [0] https://www.bbc.co.uk/food/jalapeno_chilli https://www.bbc.co.uk/food/jalapeno_chilli