So, this raises a rules question: Is it acceptable to use an English word for a dish in a non-English cuisine? I didn't think that was the case. That's why my X-entry (the German word for the food item) seemed appropriate, but apparently it wasn't for some reason.
I think its acceptable for this game. Especially if you can find a reference to the dish in English. And in any case there are hundreds of examples of English names for non-English dishes - for example 'Aubergine (or Eggplant) Parmigiana' which is 'Parmigiana di melanzane' or 'Melanzane alla parmigiana', in Italian.
The only reason I queried your yam entry for this particular game was 'cos I don't think yams are a particular German food speciality. So it would be like entering Apfle for the German 'A' or Banane for 'B'.