Place the leeks, Chinese cabbage, shiitake mushrooms, stock cube, miso, sesame oil, sesame seeds, tamari and salt + pepper in a saucepan with enough water to cover
Bring to the boil and cook on a low heat for a few minutes until vegetables are cooked
Add the tofu and cooked brown rice and mix gently so as not to break up the tofu – cook for a couple of minutes just to warm everything through