The former Beatles star - whose late wife Linda McCartney was a famous vegetarian and launched a range of meat-free products and recipe books - revealed how his family coped without turkey for their festive meal when they first stopped meat in the 70s.
He said: "We had all the trimmings but we needed something to simulate the turkey."
"So Linda made macaroni cheese. It was good, then she let it stand so it went solid and I was able to slice it."
"It kind of worked so we called it the macaroni turkey."
However, the 66-year-old singer - who lost his wife to breast cancer in 1998 - admitted he now opts for a meat-substitute dish from Linda's range.
He added: "Today we've moved on and you can buy the Linda McCartney roast."
Paul is now dating businesswoman Nancy Shevell, 47, following his bitter divorce from Heather Mills in March.
