I went to a US embassy party once here (just at a person-who-worked-there's house), and i stared in disbelief for a full two minutes at black beans in some dish he made, and then another two minutes at the big blue and red Solo cups, until he told me the embassy has its own store.

So basically, there will probably be everything you want if you are dining with the actual ambassador.

Also, Russia has a cranberry-like berry called klyukva, so if you see anything similar maybe you will luck out and it will also be cranberry-like. Do they drink mors in Bulgaria? It's kind of like cranberry juice, so you could just have it on the side or add sugar and boil it into a jelly-like concoction.

Or, what I did the other day for a pre-Thanksgiving meal involved a sauce made of pomegranates. It was very similar, but more seedy. Recommended.