The kitchen that serves the restaurant is called Production Kitchen One. A vast warren of rooms, alive with chefs, fills an area half the size of a football pitch. Each is designated for a specific purpose: cold starters and larder preparations, hot meat dishes, a fish prep area, butchery, sauces, patisserie, a bakery and a sugar and marzipan working area. Bob Salt, the lecturer who coordinates the lunchtime melee, is supremely proud of his domain. 'These kitchens are some of the best in London,' he says. 'We've got 120 chefs producing a lunch for 150 people. You won't find that sort of ratio in any other kitchen in the world.'