Nikesh Shukla’s third novel features a scene in which Rakesh, a British-Gujarati standup comedian, walks into a Brooklyn coffee shop and begins haranguing the barista: “You know chai tea latte is a redundant phrase, right? It’s cultural misappropriation. You’re pretty much serving tea-tea, like tea-flavoured tea.”

Anyone who follows Shukla on Twitter will know that his campaign against chai tea is a long-standing theme. It also formed the central tenet of his contribution to The Good Immigrant, the acclaimed anthology of essays Shukla edited in which 21 BAME writers reflected on the experience of being anything other than white in Britain today. “One of the many online arguments I’ve had about the importance of language, how language can hurt, has been about tea,” Shukla wrote. “Chai means tea. Chai tea means tea tea. The number of times you see this on a menu makes you wonder why people can’t be bothered to do their research. Like naan bread too. Bread bread.”

Rakesh’s coffee shop rant is far from the only episode in the novel in which themes from The Good Immigrant are recast – sometimes word for word – in fictional form. In his essay Shukla noted: “I have three voices. I talk in Guj-lish, my normal voice and white literary party.” Rakesh voices an almost identical statement, though “white literary party” is altered to “white comedy party”.

The self-appropriation is revealing, however, as it indicates that the experience of compiling the anthology has deepened and extended Shukla’s fictional range. He has come a long way since his debut novel, Coconut Unlimited, presented the confusion of three ethnically disoriented, privately educated British Asian teenagers who form a hip-hop band: “To prove to ourselves that we weren’t coconuts – white on the inside and brown on the outside – we tried to be brown on the outside and black in the middle.”

The One Who Wrote Destiny suggests that such neat racial stereotypes no longer apply. Rakesh toys with the idea of calling his Edinburgh show A Lovely Bunch of Coconuts, but is dissuaded by an actor friend who points out that the concept is passe: “Don’t bother dude. ‘A Lovely Bunch of Coconuts’? Who the hell wants to listen to that? I mean, being British Asian isn’t a binary thing – it’s complex, layered, nuanced … What even is a coconut anyway? It’s outdated.”

While Rakesh negotiates the minefield of racist hecklers and rigged topical panel shows, his twin sister, Neha, has entered the late stages of lung cancer and quit her job as a designer of computer systems. A solitary, celibate sci-fi fanatic, she spends her time getting quietly drunk, watching Star Trek reruns and contemplating her resistance to becoming a role model: “This is the burden of immigrants, to be good immigrants. We only become the good type once we’ve transcended the stereotypes of benefit-scrounging and job-stealing … I am not a good immigrant because my skills are not transferable. I can never transcend.”

Rakesh and Neha are quintessential Shukla characters: sardonic, slightly geeky and less ambivalent about their ethnicity than they pretend to be. Yet the most powerful writing is to be found in the framing narrative, which explains how the family originally came to be displaced from Kenya to Keighley, West Yorkshire. In the opening chapter we meet the twins’ father Mukesh, who migrates from Mombasa to Keighley in the early 1960s in the mistaken belief that he has landed in a swinging suburb of London. Instead he finds freezing mists and routine ostracism; but also the love of his life, Nisha, with whom he co-stars in a touchingly ramshackle stage adaptation of the Ramayana. There’s a terrifyingly well-handled transition in which the goddess Sita’s trial by fire becomes disturbingly real when the hall where they are performing is surrounded by a racist mob.

Nisha has pulmonary fibrosis – a genetic curse that will be passed on to her daughter – and the concluding section of the book reverts to a brief period in the 1980s in which the twins were left in the care of their Ba (maternal grandmother) on the island of Lamu in the Kenyan archipelago. The episode has the evanescent feel of a half-remembered dream; Proustian recollections of sugar rotlis blur into reminiscences of rescuing a maltreated donkey. There are dark memories even in paradise, as Ba recalls how her husband was murdered in a racist attack when they lived in Keighley, yet she castigates him for having become “the worst kind of immigrant”: compliant, deferential and so anglicised he is more English than the English.

The One Who Wrote Destiny is shot through with the anxieties and contradictions of becoming a good immigrant, yet is clearly the product of an author increasingly comfortable in his own skin. Funny, profound and by far Shukla’s most ambitious novel to date, it nonetheless heeds the advice given to Rakesh about his standup routine: “You don’t need to be the voice of all the brown people any more. There’s enough of them around now that you don’t represent all of us … Don’t ever think you need to be the voice of a generation. Because that is the quickest way to being a sell-out.”

• The One Who Wrote Destiny by Nikesh Shukla (Atlantic Books, £14.99). To order a copy for £12.74, go to guardianbookshop.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min. p&p of £1.99.