According to https://www.people.fas.harvard.edu/~gustafs/piano/Chopin/ there are only 5 pieces and none of them fit that discription except maybe the last one, I don't know if i've ever heard of it before.
Maybe s/he edited the post, but s/he never said Eb minor.The closest to a concert in Eb by Chopin is the Grande Polonaise Brillante Op. 22.Here's something that might interest you, about the movie's music (maybe it's not Chopin after all?): the music is composed by Francis Shaw who did all the music. He was up in the Italien mountains in a village; Molini di Triora. He wrote it down during a night and we recorded it on a simple tape recorder next day. The director Mikael Håfström got it by mail some days after and just loved it..... The actress (Marie Richardsson) who acted as the Mother got it and practiced a couple of weeks before we shot the scenes. In the end Francis recorded it again and it is him playing we hear in the film.
He said Eb- and that means Eb minor but it could also have been a typo.
Does Eb with a hyphen mean minor? I've never seen this before.