had been watching the tv series recently and decided to try this book. recipes are excellent. as others have pointed out, some of these take more than 30 mins - lack of Jamie's level of skills, ingredients prep time required, knowing sequence of things to do by heart! but still these have saved us significant time in the evenings after a long day's work.
if you are cooking for 2 people, either skip a dish or halve the quantities - that seems to work for us .... for the most part!
a little pre-reading helps go a long way in keeping the time down to the circa 30 mins time.