Place the chilli flakes, ginger, spring onion greens and pepper in a heatproof bowl. Stir them up, then arrange them into a small pile (this makes it easier for the small quantity of oil to interact with all the ingredients).
In a medium frypan over a medium heat, heat the oil until it’s really hot and shimmering, about 2 minutes on a gas stove. Carefully pour this hot oil over the chilli mixture. It should sizzle up and make the oil lovely and fragrant. If you’re using Korean chilli flakes, it should also take on a lovely red colour.
Add the dark soy sauce, honey or maple and black rice vinegar. Stir to combine, then taste and adjust to your liking.
If you’re using it, add the peanut butter or tahini and stir to combine.
Add the corn starch and mix to combine, then add the tofu cubes and stir to coat.
Return the tofu and all the sauce to the pan and cook for 2-3 minutes or until the tofu is heated through and the sauce thickened. Add a splash of water if the sauce gets too thick at any point. Plate up and serve.