By getting creative with whatever fresh and preferably organic unwanted produce they lay their hands on, Sarah Mewes and Sandra Teitge set up Dinner Exchange in the German capital to stoke awareness about food wastage.
Around 30 people, who do not necessarily know each other or the pair, dine at one long convivial table on a multi-course vegetarian meal in an atmosphere resembling a dinner party rather than a restaurant's formality. 'Guests' pay a €10-15 donation which goes to food-related projects.
"We also want to inspire people to be more creative with the leftovers they have in their fridge, to inspire people on a very private level at home to make better use of their budget," journalist Mewes, 29, said.
She and 30-year-old Teitge, an art curator, have been friends since high school but spent their early years growing up worlds apart on either side of the Berlin Wall.
Teitge, who was raised under communism in former East Germany, said although as a child she was not aware of missing out, her upbringing had probably left her with an ingrained aversion to wasting decent food.
"There was enough food but we didn't have a big choice, you ate what was there. My parents... always tried to eat everything and not throw anything away. We always were supposed to finish our plate," she said.
Sharing a passion for cooking, the two put their heads together to find a non-profit joint project just as a German documentary entitled "Taste The Waste" was sparking debate about the amount of food thrown away.
Behind that film was Valentin Thurn, who has also helped launch www.foodsharing.de, an online service that last month went nationwide to hook up people with unwanted food to give away with those who can pick it up and make use of it.
Thinking on our feet 'the best' bit
While Dinner Exchange guests may not know each other beforehand, they tend to be a like-minded, educated crowd who share concerns about waste – a recent study showed every German throws away about 235 euros' worth of food annually.
The unusual food and atmosphere seemed to go down well at a recent event. "I try not to waste food. I always cook something with leftovers and I freeze things because I don't want to throw them away," guest Saskia Schaudra said, taking her seat as the gong sounded for dinner.
"But I would not know the next step to be more active," the 32-year-old primary school teacher, who is also a friend of Mewes, said, enthusing about the evening's "family" feel.
"I would be happy to stroll over there, to sit down and say 'hi', although I don't know them," she added.
Inspired by a Dinner Exchange run in London by a mutual friend, the Berlin pair began in autumn 2011 initially in a spacious room at Teitge's flat and have built up agreements with several market traders. Rarely have they been unable to use what they were given, they said.
They collect the food a day before the monthly dinners meaning they have to think on their feet as they can only draw up what they hope will be a mouth-watering and inspirational menu once they see what they have.
But it's a challenge they relish. "That's the best part," Mewes enthuses. "If we were pre-selective (in our food choices) that would, kind of, ruin the creative process of it," the financial journalist, who lives in London, said, adding they tried to give their menus a theme.
Her own roots in the western border region with France inspired the buffet-style dinner of peach crepes served with four bowls of different hearty salads.
Eating seasonal, local food used to be the norm
With just a two-ring stove, the pair prepped the food in a cramped office at a trendy contemporary art space in a 19th century former hospital building in Berlin's cosmopolitan Kreuzberg district.
Their food has been dubbed "freegetarian", based on the term "freegan" for people who eat discarded edible food, and vegetarian, as their meals shun meat and fish.
They now plan to cast their net much wider with a dinner scheduled for Tel Aviv in late February, indulging a love of the Middle East and drawn by what they expect to be a receptive audience.
"I think it's a good idea to make people more aware," said another guest, Charlotte Michaelis, who works in real estate and who at home eats food past its best-before date if it is unspoilt.
The duo's leftover dining is just one of the ways unsold food can be recycled at the end of trading – alongside other anti-waste outlets or as animal feed.
Mewes and Teitge say theirs and similar projects seek to reintroduce a "basic" idea – eating seasonal, local food – which was the norm for their grandparents, and in East Germany where residents had little choice.
"Now we need books, political themes, groups and social activities that bring some very basic, rational economic concepts back on to the scene," Mewes said. "It's a very strange process."