This is the 9565th most frequent Polish word.
wschodni
Eastern.
Here, "wschodnia" is used as a descriptor of the geographic region, modifying the noun "części" meaning part.
Polska leży w części wschodniej Europy.
Poland is located in the eastern part of Europe.
"Wschodniej" modifies "kuchni" as an adjective, referring to cuisine originating from the eastern regions.
Uwielbiam potrawy wschodniej kuchni.
I love the dishes of Eastern cuisine.
Here, "wschodnim" is used as an adjective describing the "skrzydle," which means wing.