I'm not actually sure I could eat one ethnic food every day. My mother could easily eat Indian every day but I couldn't. I adore mexican and could easily have it once a week but to have every day I'd have to vastly expand my repertoire.
I think I like too many cuisines to settle on just one!
ETA - I could probably eat a helping of sushi every day, come to think of it, as long as I didn't have to make it!