To prepare, begin by thinly slicing onions and set aside.
Cut chicken thigh in bite sized pieces about 1 inch and set aside.
In a small nonstick or shallow pan, add all sauce ingredients. Bring to a simmer over medium heat.
Add in onions and chicken. Spread evenly and cover.
In a separate bowl, crack eggs and beat until smooth.
Once the chicken is fully cooked (about 5 minutes depending on size of chicken), slowly pour the beaten eggs over the simmering chicken and onion.
Cover the pan again and cook for about 1–2 minutes, or until the egg is just set but still slightly runny.
Tip: Turn off the heat just before the egg is fully cooked. The residual heat will finish it perfectly and keep it silky.
Scoop hot cooked rice into serving bowl. Gently slide the chicken, egg, and sauce mixture over the rice.
Garnish with green onions, nori strips, or shichimi togarashi if desired.