Step 1

Cut 12 ounces chicken into 1/2-inch pieces. Quarter 1 large yellow onion, then thinly slice each piece across the grain.

Step 2

Bring 1 1/2 cups water to a boil over medium-high heat in a large frying pan. Add 1 instant dashi packet and simmer for 3 minutes. Remove the packet. (If using instant dashi powder, add 1 teaspoon to the boiling water and whisk to dissolve, no need to simmer.)

Step 3

Add 1/4 cup mirin, 1/4 cup soy sauce, and 1 tablespoon packed light brown sugar to the pan, stir to dissolve the sugar, and bring to a boil. Add the chicken and onion and simmer briskly uncovered, stirring occasionally, until the chicken and onion are cooked through and tender, and the liquid is reduced by half, 10 to 12 minutes. Meanwhile, lightly beat 6 large eggs together. Thinly slice 2 medium scallions.

Step 4

Pour the beaten eggs into the pan, starting from the middle and pouring towards the outside edges in a circular motion (this ensures to cook the egg evenly). Gently shake the pan to make a marbling of the egg and seasonings for a melting texture. Cover and simmer on medium low heat until the eggs are just softly set, 3 to 5 minutes. Remove the pan from the heat.

Step 5

Divide 5 cups rice between 4 bowls and flatten the rice slightly. Gently scoop the egg and chicken mixture over the rice, doing your best to keep it together in large portions. Spoon some of the cooking liquid over the top so the rice absorbs the flavour. Sprinkle with the scallions and tear 1/2 nori sheet on top if desired. Serve immediately, as the egg will set further as it sits.