Squeamish customers, big costs: the sustainable eatery game isn't easy

Chef Peter Templehoff's spring lunch menu doesn't feature cockroaches or flies ... yet. For now the menu is everything you'd expect from one of the country's top restaurants. Templehoff's Greenhouse offering is complex, reflecting his extensive global experience while expressive of its local context.

Greenhouse is in Constantia, Cape Town, not far from the sea and other sources of good local produce. The day I visit, to try the menu and to speak to Templehoff about sustainability, I eat tuna sashimi and seaweed salad, braai bokkie tataki, local Cape fish and a fabulous piece of jersey cow beef. Pap is served as a pudding.

All the dishes are richly and deeply flavoured, often with Asian ingredients. Besides importing the few Japanese ingredients he needs to create them, he tries to get the majority of what he uses from local farmers.

Like many of his peers, Templehoff is concerned about sustainability, but doing the right thing and running a business is complicated. "I would love to be plastic free. But we rely on cling wrap."

Despite this, Templehoff and his Greenhouse team keep good practice. "We're off the grid in terms of water. We have four 1,000-litre reticulation tanks and we use all our compostables in the garden," he says.

The way forward for food security and a more sustainable future is bugs, he believes. "There is just not enough food," he says.

He's imagined insect dishes: "You'd get the taste of the broth, and the crunch of the insect." I turn my nose up at the word "crunch". He notices.

"If you're happy to eat a snotty-looking oyster, you should be happy to eat a cockroach." He's right, of course.

Esther Ndumi Ngumbi, an entomologist in the US, wrote on The Conversation that insects are an excellent tool to fight hunger and malnutrition because they are abundant, healthy, have less of a carbon footprint to produce and can offer a range of business opportunities.

She says Africa "is home to over 1,900 edible insect species - mostly beetles, caterpillars, grasshoppers, wasps and ants".

Ash Heeger's new restaurant Riverine Rabbit opened in the Cape Town City Bowl two weeks ago. Leading up to the opening day, there'd been much excitement about her new sustainable restaurant. Rumour had it that it would be a vegetarian restaurant, but it's not.

For those who have maintained a carnivorous diet, you'll be happy to know that Heeger still serves a good piece of meat. But she doesn't serve any insects, nor does she serve rabbit. So why, I ask, did she call her restaurant Riverine Rabbit?

The Riverine Rabbit is native to the Karoo, where she spent a lot of time as a child. "This endangered creature feeds off things like wild rosemary and buchus and shrubs, which we use in the restaurant. Their habitat is at risk because of over-farming."

The restaurant's name is a talking point, says Heeger. It draws attention to issues: agriculture, biodiversity, food security and sustainability.

Like Templehoff, Heeger sources the bulk of her produce locally. Her spices are from Atlas Trading Company in the close-by suburb of Bo-Kaap. Most of her vegetables come from Abalimi Bezekhaya, an NGO promoting urban farmers on the Cape Flats.

"Look at these amazing leeks, so young and tender," she says, as if talking about her children. Pointing to the greenery in her fridge, she adds: "Look at this amazing spinach."

In a cardboard box next to the fridge are big pieces of Spekboom which come from her Cape Town garden, and bunches of indigenous wild rosemary (kapok bos) from Abalimi. Boland butcher Ryan Boon supplies her with pasture-reared, sustainably sourced meat.

Heeger says: "I use the word sustainable to let people know what we're all about. But, at the end of the day, we're still a business."

The word sustainable strongly signals her ethos: "We are sustainable and we try hard to maintain that. But if being sustainable is going to send my business under, I'd put my business first."

"Sourcing the right produce is expensive," she adds. "That free-range meat, hand-caught fish from Abalobi, the wonderful vegetables we get and the wild herbs we use, it's all expensive. We pay three or four times the price of mainstream produce."

What both Templehoff and Heeger can do, and are willing to do with their particular approach to food, is promote an interest and understanding of sustainable produce and food.

Heeger believes that the more people who do this, the better. "If we grow the demand, prices will drop. The more chefs support young, local farmers, the better for all of us."

And the planet of course.

Don't be surprised if one day you find flies in one of the dishes on Templehoff's menu. "Do you know we have a soldier fly factory in Stellenbosch manufacturing fly protein?" he asks. I am not sure I wanted to know that.

• Jackie May is the founder of Twyg, a platform to inspire sustainable lifestyle choices.