In a large pot, bring the chicken broth to a boil. Add the chicken pieces and simmer for about 15-20 minutes until fully cooked. Remove the chicken from the broth and set aside.
In a separate pan, heat the sesame oil over medium heat. Add the minced garlic and ginger slices, and sauté until fragrant.
Add the soaked rice into the pan and stir-fry for a few minutes until the rice is well-coated with the oil and aromatic flavors.
Transfer the rice into a steamer tray or a heatproof dish. Place the cooked chicken on top of the rice.
In a small bowl, mix together the soy sauce, oyster sauce, salt, and sugar. Pour this mixture over the chicken and rice.
Place the steamer tray or dish in a steamer set over boiling water. Steam the chicken and rice for about 30-40 minutes until the rice is tender and fully cooked.
Once done, garnish with chopped green onions and cilantro.
Serve the Nasi Tim Ayam hot with your favorite dipping sauces or side dishes.