1. Top and tail the beans and distribute in a steamer insert.
  2. Bring water to the boil in a pan, making sure there is at least 2 cm between the water and the steamer insert.
  3. Place the steamer insert with the beans above the boiling water and cover. Steam the beans for 8-10 minutes.
  4. Meanwhile, roast the sesame seeds in a frying pan until golden brown. Peel the ginger and roughly chop it.
  5. In a foodprocessor or blender, puree two thirds of the sesame seeds, the ginger, soy sauce, mirin, sugar, salt and pepper into a sauce.
  6. Place the beans on a serving dish and sprinkle with sea salt.
  7. Spoon the sauce over and sprinkle the remaining sesame seeds on top.