In a large mixing bowl, combine soy sauce, brown sugar, salt, and pepper to create a marinade. Add the chicken thighs, ensuring they are evenly coated and marinate for at least 10 minutes.

Rinse jasmine rice under cold water until it runs clear. In a saucepan, bring water and salt to a boil. Stir in rice, cover, and simmer for 15 minutes.

Warm vegetable oil in a skillet and sear the marinated chicken for 5-7 minutes on each side until golden and cooked through. Remove and let rest.

In the same skillet, sauté onion, garlic, and ginger for 2-3 minutes until soft and fragrant.

Pour in chicken broth and rice vinegar, bring to a simmer. Return chicken to the skillet for an additional 5 minutes.

For a thicker broth, whisk cornstarch with water and gradually add to the simmering broth while stirring.

Serve by placing rice in bowls and ladling broth with chicken over it. Garnish with scallions and sesame seeds.