In the movieverse, Artificial Intelligence can be as terrifying as 2001: A Space Odyssey’s HAL or as noble as The Iron Giant, but it has seldom, if ever, been as preoccupied with cabbage as robot at the centre of this whimsical British comedy. Brian (played by co-writer and long-time Ricky Gervais collaborator David Earl) is a lonely inventor in rural Wales with a simple philosophy: “You can try things. You don’t succeed. You just got to keep trying.”

Thus, he perseveres with such unwanted and frequently malfunctioning innovations as the flying cuckoo clock, a pinecone bag, and a belt for holding eggs. One day, after happening upon a mannequin head, Brian gets to work on his greatest invention: a robot named Charles (co-writer Chris Hayward). The cumbersome creation is fashioned from various bits and bobs, including a washing machine body. Even Brian concedes that what should be a “Victoria sponge cake” is more of “a blancmange”. In the tradition of Mary Shelley’s Frankenstein, it requires a thunderstorm to bring Charles Petrescu – as he likes to be called – to life. He and Brian soon become firm friends, with the latter assuming a parental role.

The increasingly rebellious Charles teaches himself English by reading a dictionary and improbably yearns to go to Honolulu. Tragedy strikes when a clan of local bullies, the Toppingtons, kidnap Charles. Will Brian be able to stage a daring rescue? Will Charles ever see Hawaii? Will the cabbages take on a Chekhovian relevance?

Director Jim Archer’s mockumentary format dovetails neatly with Brian’s DIY aspirations and the film’s handmade, heartfelt aesthetic. There are pleasing supporting turns from Louise Brealey as Brian’s love interest and Jamie Michie as Eddie, the village tough. Brian and Charles themselves, meanwhile, make for an irresistible two-step in a delightful tale of friendship and loneliness, dramatised and written in beats that make one think of Wallace & Gromit without the clay.