The ingredient search in recipes does combine terms for British/American/Australian/Canadian English terms. You can test this with eggplants/aubergines or courgettes/zucchini.
EYB currently has about 50 indexed cookbooks in German, 5 in French, and 1 in Dutch. So you might get lucky! Although the book is written in German (for example), the EYB indexer has translated the ingredients into Englsih. The recipe titles are copied from the book -- if the book has the title in German & English, then the EYB recipe title will too. If the book has the recipe title only in German, then the EYB recipe title will reflect that.
Unfortunately, EYB does not allow one to filter for the book's language. I got my 50 German language books statistic as follows: On the Library/Books page, filter by Country/Europe/Germany & then Country/Europe/Austria. Click on "Indexed books" at the top right of the screen. The 13 Austrian books are all in German; the 46 German books are a mix of English & German language.
I hope this helps!