Tender Is The Flesh by Agustina Bazterrica

It all happened so quickly. First, animals became infected with the virus and their meat became poisonous. Then governments initiated the Transition. Now, 'special meat' - human meat - is legal.

Marcos is in the business of slaughtering humans - only no one calls them that. He works with numbers, consignments, processing. One day, he's given a gift to seal a deal: a specimen of the finest quality. He leaves her in his barn, tied up, a problem to be disposed of later. But she haunts Marcos. Her trembling body, and watchful gaze, seem to understand. And soon, he becomes tortured by what has been lost - and what might still be saved.