Start by boiling enough soba for 1 person in water for around 5 minutes. Remove the noodles once they are soft and run under tap water to stop the cooking process. Place the cooked soba into a lunchbox of your choice.
In the same pot used to boil the soba, add a packet of soft tofu that has been cut into smaller square cubes. Blanch the tofu for a few minutes. Strain the tofu and add to the soba lunchbox. Sprinkle chopped green scallion.