Place the sliced tofu on a plate and cover with half the soy sauce, flipping a couple of times to ensure even coverage, then griddle until just beginning to blacken. For this, I used my grill press, which works brilliantly because it presses out the excess moisture and you finish up with a great texture.
Put the soba noodles on to boil in plenty of water – they only take a few minutes.
In the last minute or two of cooking, chuck the bok choy leaves in with the noodles just to soften them a little, then lift back out.
Drain the noodles and place in the bottom of your bowl, top with the bok choy leaves, then sprinkle in the sliced chilli
Make up 400ml (13.5 fl oz) of stock and add the remaining soy sauce, then pour into the bowl while it’s still piping hot.
Top with the tofu, sprinkle with the sesame seeds and serve.
Raw or lightly cooked bok choy can be quite bitter. I like it, but if you’d prefer it a fully cooked, chuck it in with the noodles for the full cooking time so that the leaves wilt and darken.