Hainanese Chicken Rice comes from the Chinese subtropical island of Hainan and many of the sons and daughters of Hainan immigrated to Singapore in the past 100 years. The most-popular dish of Hainan is the Chicken Rice in which a chicken is used in all ways — poached for the meat, the soup is used to make a deliciously flavored rice and to also infuse the chile sauce. This has become one of Singapore's top loved dishes, and you will find Hainanese Chicken Rice in every street corner coffee shop and food court as well as in the coffee houses of all hotels in Singapore.
Make the Chile Sauce: Combine all the ingredients in a bowl, mix well, and season with salt, to taste. Set aside
Make the Chicken and Rice: Bring a large pot of salted water to a boil (enough water to immerse the chicken). Stuff the cavity of the chicken with the scallion and ginger. Add the chicken to the boiling water, breast side-down. Lower the heat to a simmer just under boiling point and cook, covered, until just cooked through, about 40 minutes.
Transfer the chicken to an ice water bath for about 5 to 6 minutes. (This is to arrest the cooking and will make the chicken skin crisp.) Drain. De-bone the chicken and cut into bite-sized pieces. Reserve the chicken stock, and keep hot.
Heat the oil in a wok or saucepan over high heat. Add the garlic and stir-fry until fragrant. Add the rice and stir-fry for 1 to 2 minutes. Add enough of the hot reserved chicken soup to reach 1/2- inch above the top of the rice. Bring to the boil, add the salt, and lower the heat to low. When steam holes form in the rice, cover the wok, and steam until cooked, about 30 minutes.
Whisk 1/4 cup of the hot chicken stock into the chile sauce.
Arrange the rice and poached chicken on a platter and drizzle with the chile sauce.