American director John Cameron Mitchell, best known for the musical-turned-film "Hedwig and the Angry Inch", was at the Champs-Élysées Film Festival in Paris to present his latest feature, "How to Talk to Girls at Parties". Starring Elle Fanning and Nicole Kidman, it sees an American cast decamp to the UK for a punk romance fairytale set in 1970s Britain. He spoke to Eve Jackson.