Combine the chicken, soy sauce, vinegar, garlic, onion, brown sugar, bay leaves, and peppercorns in a bag and marinate for 1-3 hours.
Heat a medium to large pot with a lid over medium high heat. Add 1 tablespoon neutral oil to the pot.
Remove the chicken thighs from the marinade (reserve the marinade) and place in pan. Brown for 2 minutes per side.
Pour the marinade into the pot. Bring to a boil, then reduce heat to a simmer. Cover and simmer for 30 minutes.
Serve over white rice and garnish with green onions and enjoy!
