When Massimo Bottura of Italy's much-lauded Osteria Francescana announced he was going to open a restaurant in Sydney, the headlines were writ large. But it was the fine print underneath that was the most interesting.

Under their non-profit Food for Soul program, Bottura and Lara Gilmore have opened a series of eating houses around the world designed to feed the disadvantaged. Here in Australia, they teamed up with the indomitable Ronni Kahn of OzHarvest to create the 13th Refettorio in the world.

"We call it lucky number 13," says Cleo Griffin of OzHarvest, who manages the restaurant with a small kitchen brigade and a team of volunteers.

Refettorio serves nourishing three-course vegetarian lunches to those who need them most, four days a week, with produce sourced from OzHarvest's food rescue program. But – and here's where you and I come in – every second Thursday evening, it opens to the paying public, who receive exactly the same food.

If I gave points for happy smiling faces greeting you on arrival, then the score tonight would beat most restaurants in town. The volunteer staff introduce themselves – tonight, we have Bianca, Diana, Michelle, Yoke and her daughter Mel – and seat diners in the buzzy downstairs room, or take them upstairs to a long, narrow dining room with timber floors and pale wooden furniture.

What was the Nepalese Kitchen has had a most handsome fit-out courtesy of a well-orchestrated and generous bunch of contributors and sponsors that sees exposed brick walls, Indigenous art, clean lines and soft colours. Building materials and labour were donated, and the building is leased to OzHarvest without charge by its philanthropic owner.

Head chef Jez Wick and sous chef Lauren Evers create weekly menus, but their ninja skills are making do with whatever turns up in their kitchen (so much harder than just putting in a stock order to suppliers).

On a rather beautiful "seconds" plate donated by Mud Australia comes a first course of potato skordalia, hemmed with herb chilli oil and topped with salsa verde, artichoke hearts, grilled broccoli and toasted almonds, with a slab of smoky grill-marked focaccia next to it. It's a clever mix of flavours that are at once fresh but familiar.

With two sittings at 6pm and 6.45pm, the rooms fill up fast, as vollies proudly inform diners that 95 per cent of the food tonight has been rescued. With no alcohol as such, dinner guests are offered house-made fruit shrub made from rescued citrus fruits, or the excellent Heaps Normal alcohol-free beer, which is refreshing and savoury. At lunch, Vittoria Coffee cappuccinos and hot chocolates are the big orders, for their warmth and comfort.

Staying with the vaguely Mediterranean vibe, the main course sees warmly spiced, turmeric-golden, bahji-like carrot and onion fritters adding crunch to a swish of creamy whipped tahini, bright green coriander zhoug, and smoked yoghurt.

It's not the food of Massimo Bottura, and nor should it be. That would be weird. It's more fitting, more nourishing, and cooked with imagination and care.

Dessert, for instance, is a slice of baby-soft sponge roulade with a heart of tangelo curd, scattered with pistachio praline and fresh tangelo that is perfect in its tea-with-Nanna modesty.

What a feel-good place. It makes you wish all restaurants were like this, with a double-life feeding others who are less fortunate, and probably a damn sight hungrier. Get behind it, Sydney. Go online to reserve a table, consider volunteering (even the barista tonight, John, is a banker by day), or book the place out for a corporate event.

The bloke at the next table gets it. "Creating a meal from leftovers is an amazing concept in itself," he says. "But here, it feeds people who need it the most. And dinners like this let us help as well."

He looks around him wonderingly. "Everyone wins." Thanks, couldn't have said it better.

The low-down

Vibe Heartfelt food-for-good venture with a double life

Go-to dish Carrot and onion fritters with whipped tahini, chickpea and zhoug

Drinks No alcohol. Filtered water, house-made fruit shrubs and Heaps Normal non-alcoholic beer.

Terry Durack is chief restaurant critic for The Sydney Morning Herald and senior reviewer for the Good Food Guide.