Step 1

Gather all the ingredients. I recommend making this dish right before you serve.

Step 2

Beat the egg in a bowl or measuring cup. Cut the green onion into thin round pieces.

Step 3

In a small bowl, mix together water and potato starch (cornstarch) to make a slurry. As starch tends to stay at the bottom of the bowl, you will need to mix again right before you use the slurry mixture.

Step 4

Add dashi to a saucepan. Add sake and salt.

Step 5

Add soy sauce and check the flavor. Add more salt if necessary and bring it to a simmer on medium heat. When simmering, give the slurry sauce another whisk and add to the dashi.

Step 6

Mix quickly to distribute the slurry sauce in the dashi. Bring it to a simmer.

Step 7

Once simmering (small bubbles around the edges), slowly pour the beaten egg into the soup in circling motion starting from the center spiraling outward (don't pour in the same area). Place your cooking chopstick at the edge of the bowl/measuring cup, so the egg will drizzle down the chopstick in a thin stream. Let the egg sit for 20-25 seconds, and remove the saucepan from the heat to prevent overcooking.

Step 8

Serve the soup into individual bowls and garnish with green onion.

Step 9

You can keep the leftovers in an airtight container or in the saucepan for up to 3 days. Reheat until warm but do not let the soup boil.