This sounds very familiar, but the only couple that came to mind was Anne Heung and Michael Miu in Au Revoir Shanghai... though I think they were Dim Sum...
(Just to be sure, what are pork buns exactly? White pastry outside, pork inside, rounded shape?)
Hint: He gave it to her. He wore it on for her. Series with Maggie Cheung. I don't think many payed much attention to this, since some parts of this series may have been boring.