Mix the tahini together with the mirin, tamari, lemon juice and ginger juice. Add water until it reaches a smooth consistency (close to pouring cream).
Bring a medium sized pan of water to the boil. Add the tofu cubes and return to the boil. Boil until the tofu cubes float to the surface of the water. Drain and blot dry.
Heat the sesame oil in a wok and stir fry the tofu until it becomes slightly golden. Set aside to keep warm and add the olive oil. Once hot stir fry the capsicum and chili, cook for 2 minutes. Add the broccoli florets and cook for a further 3 minutes, adding a little water if required. Remove from the heat. Stir through the tofu and the sesame seeds. Drizzle with the sesame sauce or serve as a dipping sauce on the side. Serve immediately.
Note: Hulled and unhulled tahini is available in health food stores. Unhulled is higher in fibre and much darker in colour. Use hulled if you can't find the other.