Book excerpt: Try me . . . test me . . . taste me . . . Joanne Harris’s Chocolat trilogy has tantalized readers with its sensuous descriptions of chocolate since it was first published. Now, to celebrate the much-loved story of Vianne Rocher’s deliciously decadent chocolaterie, Joanne Harris and Fran Warde have created the ultimate book of chocolate lore and recipes from around the world, bringing a touch of magic to your kitchen.