Book excerpt: A funny and poignant children's story from one of the world's most prolific and popular authors Alexander McCall Smith. It's all about hamburgers! Joe has just created the yummiest, juiciest, most delicious hamburger ever - and his friend Mr Borthwick wants to sell it in his hamburger shop to try and win back customers from the new fast-food place across the road. But there's a problem - Joe has completely forgotten the recipe... A pinch of this, a touch of that and a spoonful of something else...the race is on for Joe to remember!