In the first place, Margaret's translation is perfect, and it came before I even stumbled into this thread, so I will not "steal" the points.

However, both you and I believe that this deserves further explanation (mainly because the event is so local that even in the rest of Spain -beyond Catalunya- nobody knows about it (except, perhaps, some individuals).

I therefore would handle this as follows:

First of all, if at all possible, I would change the original quotation in Spanish into Catalan:

(Your translation for the German for ["Am 18. und 19. April richten die Dörfer
nördlich von Mataró das Bohnen- und
Erbsenfest aus.])

Then I would put the quotation (in the English version) in Catalan:

"Festa de faves i pèsols", and then (*)

and as a footnote:

(*) Translator's note: "Festa de Faves i pèsols" (Catalan for "broad beans and peas), is a gastronomic feast, typical (and very local) of the Maresme area (around Mataró, NW from Barceklona), where the peas especially are very famed by their taste and mellowness. Within the harvesting season (April 18 and 19), which is also the harvesting season for local broad beans, about as tasty as peas are) there is a gastronomic festival where the "guest stars" of the menus are always these, broad beans and peas (together) cooked in all sorts of recipes.

Or something about that (shorter, very probably).

But I repeat: The translation of the phrase as you put it is Margaret's, so the points go to her.

(on a side note: I agree: these are truly delicious (and deliciously and variously cooked) peas and broad beans. However, they overdo it a bit and I start questioning whether this is worth what they are charging lately)