Cut chicken thighs into bite-sized pieces (about 1-inch cubes) and season lightly with salt and pepper.

In a bowl, combine soy sauce, sesame oil, minced garlic, grated ginger, and brown sugar. Add chicken pieces, toss to coat completely, and marinate for 10 minutes.

Rinse jasmine rice under cold water until water runs clear. In a saucepan, bring 2 cups water to a boil, add rice, reduce heat to low, cover tightly, and simmer for 15 minutes without lifting the lid. Fluff with fork when done.

Heat 1 tablespoon oil in a large pot or Dutch oven over medium-high heat until shimmering. Add marinated chicken in a single layer and let cook undisturbed for 3-4 minutes to develop caramelization.

Stir chicken and continue cooking until golden-brown, caramelized, and cooked through, about 5-7 minutes total.

Pour in chicken broth and rice vinegar. Bring to a rolling boil, then reduce heat to a gentle simmer.

Slowly add cornstarch mixture while stirring constantly to prevent lumps. Continue simmering for 5 minutes until broth thickens to a glossy consistency.

Taste and adjust seasoning with additional salt, pepper, or soy sauce as needed.

Serve by spooning generous portions of fluffy jasmine rice into deep bowls, ladling caramelized chicken and broth over top, and garnishing with sliced green onions.