People have been telling me to go to Koya for months. ‘Oh, you have a page for authentic Japanese restaurants on your blog?’ they say. ‘Have you got Koya?’ And I’ve had to admit I hadn’t. Until now.

I have got some excuse for taking so long; Koya is not exactly in your face. It’s on Frith St in Soho, almost next door to Ronnie Scott’s, but you could walk the whole length of Frith St without noticing it, even if you were looking for it. Which I was. On a cold wet night in February.

One reason it’s hard to spot is that the name is written up in quite small, painted letters which don’t show up in the dark. I only spotted it by the half curtain over the door where it says koya (in hiragana).

Plus, it’s really quite tiny – or at least the frontage is. It’s a little bit bigger once you get inside as it stretches back, but it’s still not capacious and you can’t reserve so it normally has a queue outside. I didn’t have to queue because I went very early in the evening – it’s not usually as empty as this:

The point about Koya is that it’s not a noodle restaurant, it’s an udon restaurant. It doesn’t do soba. It doesn’t do ramen. It does what it does and nothing else, which is the secret to doing something really well.

It’s careful about its ingredients too, using locally-sourced produce that includes Welsh seaweed and English vegetables, and combining them with udon noodles for authentically Japanese dishes, simply served.

I knew what I wanted before I even sat down. Curry udon. Thick, white, comforting noodles sitting in a rich, flavourful broth. Plus I decided to add a tanuki topping, which consists of crispy-crunchy fried nuggets of batter.

It’s called tanuki because the tanuki ( a sort of cross between a badger and a raccoon) which is indigenous to Japan is supposed to like it. If you’re a Studio Ghibli fan you might have seen the anime Pom Poko about the tanuki’s fight to stop humans encroaching on their land. Here’s the trailer:

Oddly enough, Koya don’t do kitsune udon which in my experience is a lot commoner than tanuki udon. A kitsune is a fox and kitsune udon has a slice of fried tofu on top. I can just imagine a sneaky fox grabbing hold of the slice by a corner and making off with it… but not at Koya.

Anyway, the curry udon was excellent. With every mouthful I thought to myself, gosh, I’m enjoying this! Which doesn’t happen that often even in places with good food. ‘Curry’ is a bit of a misnomer if you’re used to proper Indian curry – the Japanese version is rich and strong but not especially hot – more warming, if you see what I mean. If you don’t see what I mean, go and try it out for yourself.

By the time I left (soon after six) it was already full with people siting on seats outside waiting to get in despite the rain. And the cold. That’s how good Koya is.