The Antipope

This novel began as a series of short sketches, which explains why it is a bit patchy, for example the Cowboy-themed barbeque section which has no relation to the rest of the book. It was also cut down from a longer work. But the main story - demonic figure arises in the London suburb of Brentford by way of five beans that grow into something very weird indeed - is good. Rankin was Writer in Residence of the Watermans Arts Centre in Brentford at the time this appeared, and there is a lot of name-checking of local places in the book including the pubs (the Flying Swan was supposedly based on the Bricklayers Arms but the geography doesn't quite fit) and the Seamen's Mission (really a former support centre for canal families). 
The lack of female characters and some racial stereotyping may sit ill with present-day readers but I don't think it's meant maliciously.
The Antipope was the first of several Brentford novels and they mostly have a freshness that is lacking in some of his later work, especially when he went to live in a Sussex village and was probably bored - Brighton suited him better.