Might be better as a black comedy *Spoilers*

The whole situation is so contrived that it would never happen in real life. The premise is perfect, Roy is a middle england birdwatching cannibal who feeds his guest chicken paste sandwiches made from his ex-wife and her lover.
McQueen is superb in comedy, such as The Thick of It.
I thought the reveal was hilarious, but it was spoiled somewhat by the seriousness of the other character and the brooding tension.