Heat a large pan or wok until hot. Add the peanut oil then ginger and garlic (and chili if using). Fry until fragrant, but don't let it brown.
Add the chicken in a single layer, skin-side down and fry until the skin is well browned.
Flip the chicken over, and then add the rice wine, dark soy sauce, regular soy sauce, sesame oil and sugar.
Cover and simmer over medium low heat for 10-15 minutes, or until the chicken is tender, flipping the chicken over a few times as it cooks.
Remove the lid and turn up the heat. Reduce the liquid into a thick sauce.
Add the Thai basil leaves and toss to coat.
Serve with rice.