Although I haven't read most of the titles on the just-announced Man Booker Prize longlist, I'd wager that the most Jewish of the lot is Joshua Ferris's To Rise Again at a Decent Hour, about an atheist dentist who longs for nothing more than to be part of a Jewish community, even while he doesn't believe in god.
Ferris was on Vox Tablet earlier this year talking about his wry, often hilarious novel. Listen here to get a taste of his droll sense of humor, his curiosity about religious experience, and how he used the story of Amalek as a writing prompt. Then, go out and get the book.