Start by making your tare – this is the flavour bomb that is going to infuse into your broth. In a bowl, combine your tahini, chilli oil, soy sauce and sugar in a bowl. Set aside until later.
Heat a little vegetable oil in a frying pan over a high heat. Get your block of tofu and crumble it with your hands over the pan so it becomes like mince. Fry for 3 mins until it's starting to crisp up, then grate in your garlic and ginger. Stir fry for another minute before adding your dark soy sauce, light soy sauce, mirin and chilli oil. Stir to combine, then set aside.
Cut your pak choi into quarters lengthways, then slice your spring onions.
Bring 1.5l of water, soy milk and soy sauce to the boil in a large saucepan. Turn down to a simmer, then whisk in your miso paste. Add your noodles and pak choi, then simmer for 3 mins until tender.
Place a quarter of your tare into the base of a bowl and add your broth. Stir to combine with a spoon, then add your noodles to the broth. Top with your pak choi, tofu, spring onions, and an extra drizzle of chilli oil if you like. Serve and enjoy.