“Those who’ve dined at Sepia would know there are certain elements of the menu that have an unexpectedness, a little surprise.” We’re speaking with Vicky Wild, who along with husband and chef Martin Benn, opened their restaurant in Sydney's CBD in 2009. She’s referring to a particularly astonishing dish on the Sepia menu; a pre-dessert ‘pearl’ crafted from a thin shell of sugar about the size of a golf ball, which when tapped with a spoon cracks open to reveal a flurry of ginger and lime sherbet ‘snow’, charming even the most serious of guests. “Something might crack or explode… There’s that whimsical nature to a lot of the dishes,” says Wild.

Before the couple opened Sepia, Martin Benn had trained under Michel Lorrain and Marco Pierre White in London, before moving on to become head chef at Sydney’s famed Tetsuya’s at just 25. He’s been swathed in awards and accolades for his complex, delicate fare and use of techniques that are needle-point sharp in their intricacy. Given the detail, the consideration of texture and the fine-tuning it takes to produce the degustation menu at Sepia, you’d think the last place Benn would want his dishes to end up is on walls, floors and the faces of his diners. But when Schweppes approached him to do exactly that to help create a new advertisement, they found the chef was more than up for the challenge.

Building on a successful 2008 TV campaign featuring slow-motion footage of bursting and fizzing water balloons, Schweppes approached Benn to create the menu for a colossal 70-person food fight, with dishes matching the adult flavours of the Schweppes Mineral Water range. The gastronomic battle was to be captured in a specially created dining room within Carriageworks and filmed in three separate “courses” – entrée, main and dessert.

“I jumped at the chance,” says Benn. “I love being challenged.” And what a challenge it was to craft a menu that took into consideration things like “splatterability”, “goopability” and the specific trajectory each dish took when soaring through the air. Benn, Wild and the Sepia team spent weeks testing out recipes for the fight. Paper targets not unlike those found at a shooting range were taped to the walls at Sepia in the hours before and after service each day. When one particular chef had an off night in the kitchen, the poor soul was used as a human target to test how the food landed once it hit him in square the face. “My whole kitchen turned into a bunch of children,” says Benn. “All the waiters were there too, and they were all in fits.”

Apart from the food’s ability to be deployed as a weapon, the taste also had to impress the participants. The 70 subjects of the ad weren’t actors pulled from a casting call, but winners of a Schweppes competition, and Benn wanted to make sure they experienced the best of his food, even if they were pulling it out of their hair. “At the end of the day, they’re still eating it,” says Benn. “They’re just going to end up eating it from all over their face and from off the walls. The flavour profiles had to be absolutely delicious.”

Once testing was complete, Benn whittled the fight menu down to include two viscous soups of tomato and pumpkin, constructed to resemble the vegetable they were created from so on the day, “when they exploded they would stick to the target’s face and hair.”

A colourful beetroot, goat’s cheese and rye tart surprise was a hit (literally), while soba noodles with a soft poached egg whistled through the air in dangly handfuls. A bombe Alaska filled with edible silver powder exploded into a shimmering cloud, as did a golden egg filled with a persimmon ‘yolk’. “As long as they could aim and throw the golden egg properly, it was really effective,” says Benn. “Some won’t be making the Australian cricket team though.”

On the day of filming in late February, a private room to the rear of the Carriageworks complex buzzed with activity. Benn’s entire team from Sepia had travelled with him to the filming to assist in creating the menu, and a makeshift kitchen had been created in one of the rooms adjacent to the dining room. Poised and dressed in cocktail attire, the “actors” listened patiently to instructions from a producer; Directions like “Don’t throw the butter, it’s way too slippery,” were hollered over the microphone, followed by “don’t be afraid to taste the food on your faces. Remember, this is a safe place to throw food at each other. Seek your inner child, not your inner aggressor.”

As the cue went off – a violently exploding bottle of mineral water fizzing all over the scene – the first handful of gelatinous ruby-red tomato ‘soup’ was thrown. Food and exploding colour flew everywhere, hitting people square in the front and back. Golden eggs ricocheted off elbows and sweet meringue from the bombe Alaska became ensnared in wisps of long hair.

Far from sitting back and observing, Wild was spotted flinging pile after pile of food from the sidelines, and the only winces from Benn came when something missed its target and instead went hurtling into a far wall. Speaking on the telephone after wrapping a 17-hour day of filming, the chef seemed weary, but exhilarated at the outcome. “A lot of my food is driven by nostalgia, without a doubt,” he says. “I think sometimes people take food so seriously, but this has brought out the kid in everybody.”

Schweppes is a Broadsheet partner. Look out for the national release of the ad from Sunday March 16.