Combine the chicken thighs, vinegar, soy sauce, garlic, peppercorns and bay leaves in a large pot. Cover and marinate the chicken in the refrigerator for 1 to 3 hours.
Bring the chicken to a boil over high heat. Lower the heat, cover and let simmer for 30 minutes, stirring occasionally. Remove the lid and simmer until the sauce is reduced and thickened and the chicken is tender, about 20 more minutes. Serve with steamed rice.
