Prepare your chicken thigh fillets by tossing them in a bowl with fish sauce and minced chili if using. Let marinate while preparing other ingredients.

In a large pan, combine vegetable oil and brown sugar over medium-high heat. Stir until melted and golden, about 3-5 minutes.

Remove the pan from heat and add the marinated chicken, ginger, and optional eschalots to the caramel. Stir gently to coat.

Return the pan to heat, cook chicken on medium, stirring occasionally for 3-4 minutes until sealed.

Pour in boiling water, bring to simmer, and cook for 10-12 minutes until the sauce reduces to a thick glaze.

Serve hot over jasmine rice, garnished with fresh coriander and additional chili if desired.