Prepare Your Ingredients (Mise en Place): Start by preparing all your components. Thinly slice the onion along its grain. Cut the chicken thighs into even, bite-sized pieces. In a small bowl, lightly beat the eggs – you don't want them completely uniform; it’s nice to have some streaks of yolk and white remaining. Divide the warm cooked rice between two large bowls.

Create the Simmering Broth: In a large frying pan or skillet (around 24cm is ideal), combine the 150ml of dashi stock, 3 tbsp soy sauce, 3 tbsp mirin, 1 tbsp sake (if using), and 1 tbsp of sugar. Place the pan over a medium heat and stir until the sugar has completely dissolved.

Cook the Onions: Bring the broth to a gentle simmer. Add the thinly sliced onions and spread them evenly across the pan. Allow them to cook for 4-5 minutes, until they have softened and become translucent, absorbing the flavour of the broth.

Cook the Chicken: Add the chicken pieces to the pan, nestling them amongst the onions in a single layer. Continue to simmer for another 6-8 minutes, turning the pieces occasionally, until the chicken is cooked through. There should be no pink remaining.

Add the First Egg Pour: Once the chicken is cooked, reduce the heat to medium-low. Gently pour about two-thirds of the beaten egg mixture evenly over the chicken and onions. Let it cook for 1-2 minutes, or until the edges are just beginning to set.

Add the Final Egg and Finish: Drizzle the remaining egg over the centre of the pan. Place a lid on the pan and cook for another 1-2 minutes. The goal is for the eggs to be softly set but still slightly runny and custardy on top. This silky texture is the hallmark of a great Oyakodon.

Serve Immediately: As soon as the eggs are cooked to your liking, carefully slide the entire mixture from the pan over one of the bowls of hot rice. Repeat for the second serving. Garnish generously with the sliced spring onions and fresh mitsuba or coriander. Serve straight away.