Celebrity MasterChef 2015: Contestants, tasks and past winners - everything you need to know

Chesney Hawkes and Sarah Harding are among the new batch of celebrities

Yvette Fielding, Patricia Potter, Chesney Hawkes, Sarah Harding and Sheree Murphy take part in Celebrity MasterChef 2015 (BBC)

Tonight sees the return of Celebrity MasterChef, meaning more inevitable sliced fingers, unintentionally raw food and decidedly dodgy presentation.

Twenty new famous faces are lined up ready to face judges John Torode and Gregg Wallace in the famous kitchen but who are they and what else do we know about the challenges they face? Here's all the key information in one handy guide:

When does it all kick off? Tune in to BBC One at 9pm tonight

How does the process work? The celebrities will take to their units in batches of five every Thursday for the Invention Test (using given ingredients to come up with their own dish) and the experience of cooking in a real restaurant kitchen. After all this chaos, they return to MC headquarters and prepare a two-course menu.

The four best chefs make it through to Friday's trickier round when they must cater for various mass groups of people. The first week's challenge is cooking lunch for 100 staff members at Legloand while others will include the All England Lawn Tennis Club (where Wimbledon is hosted) and Moorfields Eye Hospital.

These heats will continue (12 shows in six weeks in total) until semi-final week when they must endure the most nerve-racking challenges yet - catering at a Victorian feast and cooking for a Mad Hatters Tea Party to celebrate the 150th anniversary of Alice in Wonderland under the guidance of top chef James Petrie.

Final week will see the remaining contestants face John's Palate Test and the scary restaurant critics. The grand 90-minute final will pit the three most impressive cooks against each other to feed five of the UK's most revered female chefs. Then there is one last chance to prepare the best three-course meal they can to take the MasterChef crown.

Judges John Torode and Gregg Wallace (BBC)

Who won the 2014 competition? Actress Sophie Thompson cooked her way to victory last year after beating model Jodie Kidd and motorbike fanatic Charley Boorman in the final.

Other past winners include Phil Vickery, Lisa Faulkner, Jayne Middlemiss, Nadia Sawalha, Matt Dawson, Emma Kennedy and Ade Edmondson.

Who are this year's contenders?

This year's eclectic bunch features: singer-songwriter Chesney Hawkes; TV presenter Rylan Clark; actor Scott Maslen; comedian Syd Little; former Pussycat Doll Kimberly Wyatt, former Girls Aloud singer Sarah Harding; The Wanted singer Tom Parker; TV presenter Sam Nixon; journalist Samira Ahmed; professional dancer Natalie Lowe; British Paralympian world record holder Danny Crates; choreographer and former Strictly Come Dancing judge Arlene Phillips; actress Tish Potter; singer Mica Paris; actor Craig Gazey; TV presenter Keith Chegwin; actress Amanda Donohoe; TV presenter Andy Wkinwolere; actor/presenter Sheree Murphy and presenter/producer Yvette Fielding.

Meet the contestants:

Sarah Harding (BBC)

Rylan Clark (BBC)

Natalie Lowe (BBC)

Patricia Potter (BBC)

Sheree Murphy (BBC)

Scott Maslen (BBC)

Samira Ahmed (BBC)

Sam Nixon (BBC)

Danny Crates (BBC)

Keith Chegwin (BBC)

Kimberley Wyatt (BBC)

Mica Paris (BBC)

Tom Parker (BBC)

Syd Little (BBC)

Yvette Fielding (BBC)

Arlene Phillips (BBC)

Andy Akinwolere (BBC)

Amanda Donohoe (BBC)