As far as I know, My Mum is half-Australian, quarter Polish and quarter Ukrainian. My Dad? I wouldn't have a clue.. I'm guessing English somewhere down the line, but mostly Australian
I'd have to ask my parents again for exact parts, but the simplified version is: nationalities cherry-picked from across Europe, a pinch of Russian (If you're going by the "Eurasian" standard) and the blanks filled in with Shoshoni and Cherokee