This is a very complicated question for me. Race, ethnicity, nationality, and culture are sometimes not the same thing.
Charlize Theron is the best example I've ever come across to explain this. She's white, which is her race. Her ethnicity is Afrikaner, being from Dutch settlers to Africa, with Afrikaans being her first language. And she was born in South Africa, which is her nationality.
I have a similarly mixed story, and was not born in Canada, but Japan. One Japanese parent, one Austrian. I spent time in Europe growing up before coming to Canada at 10 years old. I have a hard time explaining this to others, so I normally make a joke and move on.