Orange sauce for goose
I would make it with a duck demi-glace or some simmered down duck stock, juice from a bitter orange, and perhaps a bit of Grand Marnier or other orange liquer. If you're looking for a Chinese influence, you could simmer it with a star anise or two.

There are any number of duck a l'orange recipes online (duck and goose are fairly similar flavour wise) if you need inspiration.