The judges are joined by special guest Jamie Oliver, as the contestants prepare for a season of secrets and surprises.
The home cooks compete in a gruelling two-part aquatic challenge designed by seafood master Rick Stein and centred around squid.
Contestants try to impress the judges by elevating breakfast cereals into nostalgic classics, with a pressure test awaiting the worst cereal offenders.
The chefs embark on a two-day challenge. On the first day, they have 45 minutes to marinate the base of their dish and develop the flavour. The next day, after 14 hours, they have one hour to finish their dishes.
Jamie Oliver returns to present the contestants with two difficult challenges: a 15-minute meal and his mushroom and spinach rotolo.