Pippa Middleton admits she has not tried out all the recipes in her own cookbook

Pippa Middleton has collaborated with the British Heart Foundation for her new book. Photo / Getty Images

She was widely ridiculed for her debut book - a collection of painfully obvious top tips for party-planning.

Now Pippa Middleton, the sister of the Duchess of Cambridge has risked further mockery by admitting she has not tested all the recipes in her new healthy cookery book herself.

Heartfelt, produced to raise money for the British Heart Foundation, includes a range of recipes vetted by dieticians to keep salt and sugar levels low.

And while Miss Middleton, 33, tried out some of the dishes on her family members including her parents and sister, she concedes that she has yet to make some of them herself - despite being the book's author.

"I would like to say I have made every single one, but I have definitely done a good 80 per cent of them," she said in an interview.

"I made a lot of the dishes at home."

Speaking about the critical reception of her first literary offering, she told the Daily Mail that at the time she had not yet "earned the right" to write such a guide.

Celebrate: A Year of British Festivities for Families and Friends included such tips as playing pass the parcel at a kids' party and to hold a barbecue in the summer.

It was largely panned by critics, earning just one star in the Daily Telegraph.

"I believed in it and can't blame anyone else, but maybe it might have been better if I had waited a bit longer before doing it," she said.

Miss Middleton, who recently became engaged to hedge fund manager James Matthews, also revealed that early on in her relationship she had impressed him with a "special dinner" - a dish of halibut with roast tomato and herb dressing.

She said the couple prefer to eat at home rather than dine out at expensive restaurants and spend their spare time living an active lifestyle.

This summer she scaled the Matterhorn in Switzerland with her brother James in memory of her fiance's late brother, who died in 1999 while descending Mount Everest.

Meanwhile her husband-to-be has previously completed the gruelling Marathon Des Sables, and the pair have done a 50-mile swimming and running race together.

"I think we do exhaust most people," she joked.