Chocolate sorbet with preserved ginger, orange and sesame caramel

Disorganized by nature, especially at the end of a meal, I have ignored my ice-cream making machine for a year now, preferring to buy delicious ice-cream desserts from a good specialist. This very easy recipe from the River Café in London should reconcile me with the blasted machine which in my hands has so far made either iced soup or sticky ice cubes...