Whisk together the oyster sauce, soy sauce, fish sauce, and brown sugar in a small bowl until the sugar dissolves.

Heat a large wok or skillet over high heat until smoking slightly.

Add vegetable oil and swirl to coat the pan.

Stir-fry minced garlic and sliced chilies for 15 seconds until fragrant.

Add ground chicken and break it into small pieces with a spatula.

Cook for 4 to 5 minutes until the chicken is browned and slightly crisp.

Pour the sauce mixture over the chicken and stir to coat evenly.

Cook for another 2 minutes until the sauce forms a glossy glaze.

Turn off the heat and fold in the fresh Thai basil leaves.

Toss for 30 seconds until the basil wilts.