"What are the traditional foods in Anatolia?"
Translation:Anadolu'daki geleneksel yemekler nelerdir?
Anadolu'daki geleneksel yemekler nelerdir = What are the traditional foods that are in Anatolia? What are Anatolia's traditional foods?
Anadolu'da geleneksel yemekler nelerdir = In Anatolia, what are traditional foods?
So in the -daki sentence, you're asking about traditional foods that are in Anatolia. In the -da sentence, you're asking in Anatolia, about traditional foods in general. Presumably, you mean what the local traditional foods are, but you might also be asking what people in Anatolia understand by "traditional foods" - and you might get information about traditional Chinese cuisine from the point of view of an Anatolian.
Just like verbs and every other instance in the Turkish language, the plural market is optional on the verb (or predicate in this case) if you have a plural subject. Otherwise it is not necessary. :)
The -re actually is a suffix that to do with forming places. It is seen in a few places, "burada" "orada" "nerede" for example :) However, if you want to have this construction in the nominative case, you must use the 3rd posessive suffix "burası" "orası" "neresi"