Cut the tofu, spinach, and mushrooms
Bring the dashi to a boil, then add the vegetables and grated ginger
Season with soy sauce and salt
Mix the potato starch with double the amount of water, then stir it into the boiling soup
Keep it at a gentle boil and slowly drizzle in the beaten egg
Serve in a bowl and top with sliced green onion and shichimi if you like
