Cook the rice following the pack instructions, then drain and keep warm. While it’s cooking, place the chicken breasts into a pan of boiling water so they are completely covered. Boil for 1 min, then turn off the heat, place a lid on and let sit for 15 mins. When cooked through, cut into slices.
Boil the broccoli until tender. Drain, rinse under cold water and drain again.
For the dressing, mix the miso, rice vinegar, mirin and ginger together.
Divide the rice between two plates and scatter over the spring onions and sesame seeds. Place the broccoli and chicken slices on top. To finish, drizzle over the dressing.