The star of the BBC's Saturday Kitchen will join patissier Eric Lanlard to run the cookery classes aboard the P&O Cruises 3600-passenger vessel Britannia.
The ship's restaurants will have creations of chefs Marco Pierre White, Atul Kochhar and Olly Smith.
P&O Cruises said the ship will sail on its maiden voyage from its home port of Southampton on March 14 next year. The 14-night Mediterranean voyage will include stops at Barcelona, Monte Carlo and Rome.
After it is built in Italy, the ship's maiden British Isles cruise will be a 12-night voyage starting on July 6 2015 and including Edinburgh, Glasgow, Liverpool, Dublin and Cork.
The opening season for the 1837-cabin vessel includes sailings to the Caribbean, the Baltic and the Canaries.
Britannia will feature a children's club, 13 bars and 13 different places to eat, a spa, a sports arena, four swimming pools, entertainment arenas, a dance hall and an art collection worth more than £1 million. All outside cabins have balconies and there are 64 suites.
P&O Cruises marketing director Christopher Edgington said: "Britannia will introduce cutting-edge design, combined with a range of innovations."