Heat a wok over high heat. Pour in oil and when it's hot, cook the chicken breast until the meat is no longer pink, for about 1 minute. Then add ½ tablespoon of Kecap Manis. Cook for 1 minute. Set aside.
Heat a clean wok over high heat. Pour in oil and add chopped yellow onion, cook until translucent. Add the sambal paste, and cook until fragrant for about 30-40 seconds. Keep stirring to prevent burning.
Add the cooked chicken back into the wok and pour in the cooked white rice. Keep shaking the pan and stirring.
If the rice is a bit too dry, add about ½ tablespoon of unsalted butter.
Add 1 tablespoon Kecap Manis and ½ teaspoon salt. Toss the rice to coat and keep stirring for about 2 minutes or until the rice starts to caramelize.
Adjust seasoning if needed. Turn off the heat and serve with Acar Timun, fried egg and fried shallots. Enjoy!