Sometimes you see a movie where (factual content and (emotional)effect are strongly in opposition to each other. For example, in 'Pulp Fiction' the content includes a lot of random and 'accidental' violence, even against totally innocent people, but the way it is portrayed prevents you from taking it seriously. It is like the violence in a cartoon such as 'Tom and Jerry'. It provokes laughter rather than disgust.
Dumplings is such a movie. It portrays a young (sort of) woman: 'aunt' Mei, who earns her living making dumplings that rejuvenate the eater, effectively giving him or her eternal youth, as long as they are regularly eaten. Now the catch is in the 'special ingredient'. I won't reveal what this secret ingredient is (although it becomes clear very early in the movie) but it is one of the sickest ingredients that I have ever seen, read about or heard of. The unique feature of this movie is that it is able to utilize this horrible element without becoming a movie that is either simply disgusting (like 'Braindead') or slapstick (such as 'Ichi the Killer'). On the contrary, it is actually a quite funny story about the interaction between Mei and her clients and about their increasing dependence on her dumplings.
But what makes the movie really worth it ( to me, at least) is social commentary that it includes. The real issue is not the 'special ingredient' of the dumplings, but the fact that people are so desperate for 'youth' that they're willing to do everything for it. In a society totally focused on the external norms (like wealth, beauty, and appearance) it is no surprise that the internal norms (like law, morals and compassion), atrophy and get discarded like a snake discards his old skin. This externalization of norms, however, is not criticized or punished, but rather advocated (by the film, not necessarily by its maker) as natural and acceptable, indeed inevitable. It is this highly subversive and thought-provoking element of the film that makes it truly worthwhile.