I know you said you wanted something similar to a Hungarian Dance, so you can freely disregard my suggestion if you want to. But honestly, I also think something like Pachelbel's Canon in D would be a good selection too. Even though you might have to shorten it, if you make what you do play elaborate and polish it well, it could turn out to be a great success. You and the violinist could also try things such as having the piano playing slightly more softly in some places and the violin softer in others, bringing out the part of the melody you're trying to emphasize at that moment. Just a thought.
Hope this helps!