Lawson's Nigella Quick Collection app has also been updated with 30 additional recipes, with 20 of these exclusive to the app. Chatto & Windus editorial director Clara Farmer added that the e-book of Nigella Christmas will be released later this year.
The e-book editions will be in full colour, with recipes categorised by food groups and an interactive list of dishes at the beginning of each chapter to preview the content.
At the time of writing, the Kitchen e-book was priced £13.66 on the Kindle store and £12.99 on the iBookstore, with Nigella Express priced £10.77 on the Kindle store and £9.99 on the iBookstore. The e-books will also be available through the Random House site, priced in line with their latest physical editions.
Farmer said: "It's wonderful to be building on the huge success of the Nigella Quick Collection app with this sumptuous update—giving fans even more fantastic, fast recipes—and to be launching two of Nigella's cookbooks as e-books, elegantly adapted for digital devices, for the first time."
Published by Vintage Digital, they have been designed by The Random House Group in-house