"I love a Sunday roast on a Tuesday, Wednesday and Thursday," the Roar singer said when asked what she'd like to have delivered to her backstage at Capital FM's Jingle Bell Ball.
She also listed "nice warm meat pies and Yorkshire puddings" as her favourite British dishes.
The 29-year-old songstress also spoke of her love for Christmas tradition in the UK, "I am very excited to be spending the holiday over there, you guys have a great tradition."
She joked, "I'll be getting fat."
The California Gurls singer will headline the first night of the party with Tinie Tempah, Ellie Goulding, Rizzle Kicks, Olly Murs, Union J, James Arthur and Naughty Boy also performing.
Tinie Tempah revealed that he was looking forward to checking out Katy's backstage area which he says is famed for its sweet aromas.
"I've heard it always smells of candy floss and sweets. Yeh, I'm so into that. My nose will definitely be getting stuck in there."
Starry Eyed singer Ellie said she was looking forward to catching up with Katy.
"She's a mate of mine," the 26-year-old. "I've just stayed with her actually. We did a show at Hollywood Bowl in LA and we performed Roar together which was quite funny.
"It's always good to be a part of a line-up of people you know and love."
Capital's Jingle Bell Ball, which takes place on 7 and 8 December, raises money for the station's flagship charity, Help A Capital Child.