This is a wonderfully simple, almost exotic light meal that fills you with a big smile. Make sure you get really fresh tuna – it needs to be red and almost waxy-looking.
You can try using different fish, such as salmon, bream or scallops, just make sure they’re all really nice and fresh and smell of nothing but the sea.
Get your tuna, and with a long sharp knife slice it as thinly as you can. Once you’ve sliced it, you can smooth it over with the side of your knife to make it even thinner. Divide this in one layer between your plates, or it’s even nicer to serve it on one big plate.
Next, use this brilliant Japanese trick: cut a V-shaped vertical slit in the mooli and stuff the chilli in. This means that when you grate it you get a pink-coloured, chilli-flavoured radish pulp, which is fantastic. If you haven’t got mooli you can get the same effect by finely chopping the chilli and grating normal radishes.
So, either grate or chop your mooli or radish and then blob it and its juice over the tuna slices and sprinkle over the shiso or coriander.
When you serve it squeeze half a lime and a couple of teaspoons of soy sauce over each portion, to taste, then drizzle with a little olive oil.
* Shiso is a Japanese herb with a strong flavour reminiscent of aniseed.