There is a reason the diners can't see into the kitchen at Swad in Melrose Arch. They would be appalled at the smoking pans, the huge jets of blue flame from the gas fires, and the speed and violence of the cooking process.
Surfaces are covered with small bowls of spices, a woman is peeling a mountain of prawns, a man pounds peas wrapped in a cloth, and the chefs are constantly tasting and conferring in Hindi and Bengali over pots of steaming curry.
The kitchen this week made space for two more chefs: Madhav Chandra Pal (57) from Kolkata and Arvind Rai (48) from Uttar Pradesh. They flew into Johannesburg to help to prepare for the restaurant's festival of Bengali food, which is on until February 11.
Ahead of the opening night earlier this week, at least five dishes are being prepared simultaneously. Chef Pal is washing out a giant karahi (cooking pot) over at the sink. He hefts it back to the gas burner, and calls out: "Lighter? Lighter?"
Pal, a slight man with a tattoo – his name – on his right arm (which he says with a little regret he got when he was much younger) is wearing smart black formal shoes, much smarter than the other kitchen staff, and he has beads of sweat around his nose.
He reaches down and, using his whole arm, his whole body, spins the wheel under the burner and ignites the flame. It's like the engine of a Boeing, and envelops the bottom and sides of the karahi in blue flame. He pours an improbably large amount of oil, a big bowlful, into the pan, and then waits.
The volcano under the pan roars away. He gets a faraway look in his eyes, waiting for the oil to get hot enough, and slowly starts to collect his ingredients.
He selects four or five giant red chillies, throws them in, and a big handful of kalonji, or onion seed. The oil is now smoking dangerously. A small plastic bucket of poppy seed paste goes in too and a cloud of thick white smoke explodes out of the pan.
He just keeps stirring with a small metal spade, then adds turmeric, some water, a handful of salt, and a giant colander of sliced banana. He stirs some more, and offers me a taste: it's hot, creamy and rich all at the same time – and not at all sweet – unlike anything I've ever tasted.
Bengali cuisine is not often prepared outside of India, and is more piquant than the more popular southern and northern styles of cooking that are now found all over the world. Bengalis use mustard oil a lot, and onion, as well as poppy seed.
Another typical dish is fish (they use thin slices of kingklip) marinated in salt, pepper, garam masala, garlic, mustard and turmeric, which is then wrapped in banana leaves and steamed. The leaves and spices impart a kind of emerald taste to fish.
Perhaps Bengal's most famous invention is the spice mix paanch phoron, made from equal quantities of the seeds of fenugreek, cumin, mustard, nigella and fennel. It can be added to beef or vegetable curry, and will add a slightly bitter, savoury note.
Chef Rai says they brought all their spices from India, and is quick to say that, although everything is available in South Africa, they wanted a "typical Indian taste".
Rai is with the "VVIP" catering unit at the Ashok Hotel in Delhi, and says he regularly caters for 4 000 or 5 000 people attending conferences. Prime Minister Manmohan Singh is also a regular. His favourite dish is lightly fried fish and, as a diabetic, he orders sugar-free deserts.
And so the cooking goes on: a few bottles of deep-yellow mustard oil are poured into the karahi and, when it's hot, about a kilo of sliced red onion, which is fried for about 20 minutes until it is a deep brown. Then 5kg of cubed mutton, garlic and ginger paste, a few handfuls of dhania powder, a masala that I don't recognise, a handful of salt, and turmeric.
This dish is cooked for well over an hour, with tastings every 10 minutes or so. It's dark and richly complex, and Rai takes a spoonful of meat over to Pal. Pal shrugs, which appears to mean the dish is on track, and has everything it is supposed to have. He turns back to his board – the chopping is never done.
The meal – two starters, five main courses and two desserts – will be served buffet-style at Swad in Melrose Arch, and costs R205 a person. Phone 011 684 1007