American Jewish novelist AM Homes has won this year's Women's Prize for Fiction, beating favourite Hilary Mantel.

She was awarded the £30,000 prize for her novel May We Be Forgiven, about the relationship between two brothers. Its main character Harry is Jewish and the novel deals at times with questions of religion.

"It was so fresh and so funny – darkly funny – and so unexpectedly moving," said. Judging panel chair Miranda Richardson. "You're laughing in kind of fear or horror as much as anything else. It's relentless, but great."

The author said as she collected the award that it was her nature "to think about big ideas and my gender shouldn't prevent me from doing that".

The author, who was one of five Jewish writers longlisted for the award, was adopted by a Jewish family as a child.

She has previously written a memoir that addresses her Jewish identity called 'The Mistress's Daughter, while other well received books include This Book Will Save Your Life, a satire of life in Los Angeles.

Speaking about the book, Ms Homes has said that she deemed it something of a risk to explore a Jewish subject in fiction. "I thought this will be my Jewish book and people will be upset by that," she told an interviewer. "But the secret, or the truth, is that I'm incredibly happy about it."