Sanxia Renjia, 36 Deptford Broadway, London SE8 4PQ (020 8692 9633). Meal for two including service: £50-£75

There is just one other person at Sanxia Renija, in Deptford, when we arrive for an early dinner. He is alone, working his way through a quarter of crispy duck and pancakes. Oh dear. On the one hand, being judgmental about other people’s menu choices is unkind. On the other, what a schmuck. Going to an arse-kicking, cheek-slapping, thigh-spanking, gloriously ring-burning Sichuan restaurant like this and ordering the crispy duck is a little like popping into a brothel and paying for a chat. Of course you can do that. It’s your money. But it is rather missing the point.

Sanxia Renjia is part of a three-strong group – the others are on Goodge Street in central London and in Bromley, southeast of the capital – celebrating the food of Sichuan and Hubei. The name refers to the Three Gorges area along the Yangtze River. I know this because the main menu comes with bits of commentary headed “cultural note”. I know of other restaurants of this kind, which only list the good stuff in Chinese; where the waiters roll their eyes if you try to order some of the more intriguing-looking things being served to eager Chinese families nearby. They tell you that you won’t like it, that it’s not for you.

Sanxia is on a different mission. Yes, they do have a list of Cantonese standards. The unadventurous of Blackheath must have their hit of sweet and sour pork. But the staff, like the rest of the menu, are eager. They want you to march across unexplored territory. It appears they even managed to convince Mr Crispy Duck. As he was paying, we heard him complaining that the chicken with red chillies had a greater volume of chillies than chicken. Which is exactly as it’s meant to be. The drifts of crisp-fried red chillies are there for the aromatics, to be dug through in search of the treasure. They are not there for eating.

They are, however, very pretty, which is great because the room isn’t much of a looker. The big light is on. The floor is a white marble slab, as if it’s an airport baggage reclaim hall. Outside the traffic thunders by, on its way to places too manicured to inspire a song by Squeeze. Pay attention instead to what is in your bowl. What’s most striking about the food here is the commitment to light and shade. Dinner in a Sichuan restaurant is usually food as action movie. It’s all bash and crack.

But there are defined moments of subtlety here, too. From a list of “clay pot” dishes, for example, comes seafood and tofu, in a velvety broth full of the restorative hit of ginger. Almost everything in this bowl is pale and interesting. It’s Chinese food as designed by The White Company. There is the pearly white of the scallop and of the fish ball, of the slashed and curled squid, and best of all of the silken tofu. This is balanced between solid and liquid. It slips from bowl to spoon – don’t even think about doing this with chopsticks – to mouth. It soothes the throat and caresses the soul. It’s a dish that makes you think you know how to live forever: just eat a serving of this every day and the Grim Reaper could never claim you.

We have similar feelings about the black fungus salad with its dressing of fresh red chilli, sesame oil and vinegar. The fungus is both slippery and crunchy. It is gaspingly, achingly fresh. Likewise grilled green peppers, tossed with black beans, soy and vinegar, are like padrón peppers that have been hanging out around the back of the bike sheds with the tough boys, learning brilliantly filthy habits.

From the darker side of the ledger we get the classic ma po tofu. This time the bean curd is in denser, more robust cubes which lend themselves to a bit of chopstick action. They are swimming in a sauce the colour of rusting pig iron. It is a big punch of fermented broad beans, chillies and black beans. There are unfathomable depths of flavour here. It is a culinary Mandelbrot set, the flavours – of umami and salt and chilli and more umami and more salt and more chilli – unfold endlessly into the echoing crevices of my head. I have a reasonable tolerance for chilli heat. I enjoy the burn. My body, however, likes to undermine me. At a certain point I go into an uncontrolled flop sweat. The ma po tofu is what turns the waterworks on. Gently I begin to dissolve at the table.

There is a list headed “Adventurous dishes” which, like the best menu writing, has the quality of exquisite found poetry: there are fried chicken gizzards with wild chilli or boiled pork blood curd Chongqing style; there is Dongpo stewed pig’s joint and hot pepper fried pork tripe. My friend Tim Anderson, the regular panellist on BBC Radio 4’s Kitchen Cabinet and the chef behind Japanese soul food restaurant Nanban, was responsible for sending me here in the first place. He insisted that, from this list, I try the dry fried pig’s intestines, with dried chilli and Sichuan peppercorns. I do as I’m told. This is fried food which demands attention. The crisped bits of piggy inside have a crunch that gives way to a hit of glorious offal pong. It’s like andouillette that’s been away on a gap year, got a tattoo and started smoking dope to prove it. The lesson here is: always listen to Tim Anderson.

At the front of the menu they offer hot pots, both the stock-based kind at £22 a head and the more intriguing “aromatic, spicy and numbing”. There are long lists of ingredients at between £4 and £6. You order a minimum of four and they knock the whole thing up. We chose pork belly, squid, chicken breast and broccoli. My suspicion is that whatever you choose, it will still taste the same: a huge, dry, meaty hit of chilli and peppercorns. The latter are especially pungent. I’ve had the Sichuan peppercorn tingle before, but these make half my mouth develop acute, giggly pins and needles. This cheerful, brawling hoodlum of a dish shoves us over the top.

In an effort to shake down the menu we have ordered too much. No matter. They box it up and we fry it in a wok for brunch the next day. That’s a hell of an awakening. But it’s probably enough excitement for one month. My mouth needs a rest. I need a rest. Next week: time for a bit of old-school classic French.

Jay’s news bites

■ Wuli Wuli, in Camberwell, south London, is a small but perfectly formed Sichuan restaurant. They do a brilliant line in pork dumplings dressed with chilli oil, alongside twice-cooked pork slices with chilli or fragrant special Szechuan dry spare ribs. Their takeaways are a regular arrival in my home (wuliwulicamberwell.co.uk)

■ New product discovery: Cheesepop. Pieces of Emmental or Gouda, dried and then popped in some curious manner they won’t explain to me. It launched in the Netherlands in 2014 and is now slowly arriving in the UK. (I got it from Guzzl in Brixton village). It’s like the best bits torn off well-done cheese on toast (cheesepop.com).

■ Billy Wright, 2016 MasterChef finalist, is to run a 24-hour supper club at Plum + Spilt Milk in London’s Kings Cross, in aid of Cancer Research UK, after he was diagnosed with a rare form of cancer. He and his business partner Jack Layer will cook from 11am on 3 February, with nine sittings in 24 hours. Visit design mynight.com and search Billy and Jack’s 24-hour supper club.

Email Jay at jay.rayner@observer.co.uk or follow him on Twitter @jayrayner1