One of the most celebrated dishes on the menu at Nobu, the black cod, is dismissed by Yuki with a smiling shake of the head as “common, everyday food for us in Japan.”

I’ve just sat down in the airy, white kitchen of her Victorian flat in Crystal Palace where she has invited me to take part in an evening learning about –and how to make– miso. It’s one of the many courses that chef, food writer and cookery teacher Yuki Gomi runs from her home, educating and spreading the word about Japanese food and techniques.

I’m the first of six to arrive, the rest soon follow, all men. Perhaps it is the slight geekiness of fermenting things in jars that attracts them; she says that she thinks it’s the first time she’s had an all-male group. There is a studious quiet as Yuki, animated and full of friendly enthusiasm for her subject tells us all about the process of miso making and gives us a quick tasting of five different types ranging from the sweet ‘Kyoto miso’ with a smooth texture –the one used in the black cod dish– to the impenetrably inky red and deeply savoury hatcho miso which, she says, is particularly good for ramen, the darling dish of Shoreditch.

The vast majority of miso is made from fermented soy beans, but as she explains, it is the ‘koji’ that makes the difference. This is a mould that can be from rice, red beans, or wheat, and barley, each one lending subtle yet distinct differences to the resulting flavour. It’s used to make sake, rice vinegar and many more Japanese dishes.

Miso is one of the core ingredients in Japanese cooking, giving it the Umami taste we all know about these days from things like Parmesan or even fish sauce. It’s that savoury note, rich and deep that gives things body. It also stimulates dopamine release in us while eating, which helps give a feeling of satisfaction or fullness. This is one of the reasons why, Yuki explains, that the Japanese don’t tend to overeat.

Making it is such a simple process, but there is great complexity at work beneath the surface and each yearly batch can vary she tells us, much like wine. You can only control fermentation to a certain extent.

We all laugh a little as she tells us that Umami translates literally as ‘tasty taste’ which to me sounds like a great name for a restaurant. Miso is admittedly an acquired tasty taste, but nonetheless, that is an accurate description. It lingers long and deliciously on the tongue. And each variety, you can tell, would suit some dishes over others.

As Yuki talks, she is a blur of activity. Chopping, rinsing, darting back and forth to the sink. We sit sipping from small ceramic tea cups the delicate barley tea called mugicha she has made us. In what seems like only a few minutes she presents us each with a little bowl in which is nothing more than a small pile of cooked, sliced choi sum, a halved boiled egg, some sesame oil and a spoonful of her magic umami soy sauce made from koji, salt and soy sauce left to ferment in a corner of the kitchen. It is a wonderful thing, simple yet deeply flavoured. A real bowlful of tasty taste brought together with the minimum of fuss.

Mistakenly, however, I had eaten a rather hearty supper with the family just before coming out. Fortunately this was light enough to manage. But there was more to come. I wasn’t going to miss out though, so, with great courage and determination, I finished the –what seemed like a huge bowl of– mushroom, tofu and vegetable noodle soup. Both dishes illustrated the depth of flavour miso gives. Ladlefuls of it went in, melting into the hot dashi broth and the result was comforting, savoury and if I wasn’t already full, satisfyingly filling.

After a few quiet breathing exercises in the corner and the loosening of a notch on my belt it was time to burn off some of the food. Even with a stick blender the mashing of the beans took serious effort. The salt, rice koji and cooked soy beans coming together, eventually, like a thick humous. Every so often Yuki would throw in a little of the soy bean cooking water to help loosen the mix, telling us as she did so that it contained plenty of natural sugars from the beans which would greatly encourage the fermentation. More immediately, it greatly encouraged the ease of blending.

It didn’t take long for us to fill our glass fermentation jars once she was satisfied with our efforts. We splatted the miso in from height to avoid the risk of air bubbles and bad mould growing. And that was pretty much it. A little careful tending every so often over the next twelve months and it will be ready. This really is a lesson in patience.

If I’m going to make enough to last 2021, I’d better get on with some more. It’s made in the colder months of the year so the fermentation is slower and more flavour can develop. The London climate is pretty much perfect for this, Yuki says as we leave, putting our shoes back on in the hall, standing and hopping like a bunch of ungainly middle-aged pelicans. But we are all enthused by her excitement and passion for this simple jarful of flavour made from just three ingredients and time.

She only runs her miso class in January and February and this makes me think. I must get home and try and make a bigger batch of this for 2021 before spring temperatures start to climb. That way, come next year, in the bleak cold near the end of a long winter, I will have plenty to savour.

For details of Yuki’s classes and more: https://www.yukigomi.com