Heat a drizzle of oil in a large skillet or pan over medium heat. Add the sliced onion and cook for 3–4 minutes, until softened and lightly caramelized.
Add the minced garlic and sauté for about 30 seconds, until fragrant.
Add the chicken thighs skin-side down. Cook for 3–4 minutes, then flip and cook for another 3–4 minutes, or until the chicken is nicely browned on both sides.
Pour in the Coca-Cola, then add the dark soy sauce, soy sauce, oyster sauce, Shaoxing wine, and white pepper. Stir gently to combine.
Reduce the heat to low, cover, and simmer for about 15 minutes, allowing the chicken to cook and absorb all the savory-sweet flavors. Flip the chicken so all sides absorb the sauce.
Remove the lid and continue cooking for a few more minutes, allowing the sauce to reduce and thicken. Spoon some of the sauce over the chicken as it reduces.
Garnish with sliced green onions and serve hot.
Enjoy!