Combine dashi, soy sauce, mirin and sugar in a medium-sized pan
Bring the mixture to a simmer over medium heat, stirring occasionally until the sugar dissolves, about 2 minutes
Add onion and chicken
Add the sliced onions to the sauce and simmer until onions are tender, about 4 minutes
Add the chicken pieces to the pan and cover the pan. Let it simmer for about 6 minutes, until the chicken is cooked through.
Prepare the eggs
Crack the eggs into a small bowl and lightly beat the eggs until the yolks and whites are combined.
Cook the eggs
Slowly pour the eggs over the chicken in the pan. Using circular motion, try to distribute the eggs evenly.
Cover the pan and cook for another minute until the eggs are just set but still slightly runny.
Serve
Place a portion of cooked rice in a bowl and spoon the chicken and egg mixture over the rice. Tip: add some sauce as well for more flavor!
Optionally finish with shichimi if you like some spice!
Notes
Tip: the eggs can be fast to cook, so keep your eye on it! Lean towards taking the pan off the heat earlier than later, as the eggs continues to cook on the bed of rice.