01 - Prepare all ingredients. Begin cooking rice first if not already prepared.
02 - In a large, deep skillet or donabe, combine dashi, soy sauce, mirin, sake, and sugar. Stir and bring to a gentle simmer over medium heat.
03 - Add sliced onions and cook until softened, about 3 minutes.
04 - Layer chicken pieces over the onions. Cover and simmer for 6-8 minutes until chicken is cooked through.
05 - Pour beaten eggs evenly over chicken and onions. Cover again and cook for 1-2 minutes until eggs are softly set but still slightly runny.
06 - Spoon hot rice into serving bowls. Gently slide portions of chicken, egg, and sauce over the rice.
07 - Garnish each bowl with sliced spring onions. Serve immediately.