The discovery of chocolate

by James Runcie

From the author's site (see link): The Discovery of Chocolate is a comic, philosophical love story about one man’s five hundred year obsession with love and chocolate. Twenty year old Diego de Godoy travels from Spain to Aztec Mexico with the conquistadors. But instead of coming back with gold he returns with chocolate and discovers that both he, and his greyhound Pedro, have accidentally drunk the elixir of life at the same time. As a result they are condemned to travel through time, unlucky in life and in love, but ever hopeful that one day they will understand the meaning of their journey.