Ms Lim said she had a friend for whom Ronald McDonald House in Auckland had been a lifesaver, so she understood how valuable the retreat must be for families of seriously ill children.
Tonight's event begins with an auction at the Novotel, where guests have the chance to bid for their eight-person table to enjoy a six-course meal cooked by Ms Lim at the lakeside retreat. The other 25 tables of guests will dine at a restaurant drawn at random.
Highlights of Ms Lim's menu for tonight include a beef carpaccio starter and a main option of duck with kumara and plum sauce. The menu will reflect her philosophy of balancing healthy, fresh, in-season ingredients with delicious flavours.
She believes it's that balance that has made her book so popular - it surprised both her and her publishers by going to re-print after just three weeks on the shelves.
"It's also quick and easy recipes, so it ticks all the boxes that people are looking for."
A second book is already in the pipeline, which further builds on her philosophy of not just what to eat but how to eat.
Ms Lim says she has seen only a few episodes of the current Masterchef series, featuring Rotorua's Charlene McGechan.
"I don't really relate to it anymore, it seems so long ago," she said.
"But I watched one where the butcher [Matt] was trying to [caramelise] some sugar and I was yelling 'add some lemon juice' - it was frustrating."
However, she said, Rotorua could be proud of Charlene. "She's doing really well, she looks the pick of the bunch."
NADIA'S TIPS FOR WINTER
Make a big pot of soup then separate into portions and freeze in ziplock bags. That way you can take one every day for a hot, nourishing lunch.
Make the most of the awesome in-season winter veges - artichoke, celeriac, parsnip, leeks and parsnip are under-rated and make lovely soup.
Spice up winter. People crave curries and spicy food when it's cold so use lots of spices.
Don't forget fruit. We often don't eat as much fruit in winter but warm fruit compotes using tamarillos, oranges or kiwifruit are delicious.
Start the day with warm breakfasts. Try semolina pudding if you get bored with porridge.