In a bowl, combine soy sauce, brown sugar, sesame oil, and black pepper. Add chicken thighs and marinate for at least 15 minutes.

Heat a skillet over medium-high heat. Add the marinated chicken and cook until caramelized and cooked through, about 6-8 minutes per side. Remove from skillet and set aside.

In a large pot, heat a little oil over medium heat. Add minced garlic and grated ginger, sautéing until fragrant, about 1-2 minutes.

Pour in the chicken broth and bring to a simmer. Add rice vinegar and sliced green onions. Let simmer for 10 minutes.

Rinse the jasmine rice under cold water until the water runs clear. In a rice cooker or saucepan, combine rice and water. Cook according to rice cooker instructions or bring to a boil, then reduce heat and simmer for 15 minutes.

In bowls, add a serving of rice, top with caramelized chicken, and ladle the garlic ginger broth over the top. Garnish with additional green onions if desired.