Add the chicken thighs, soy sauce, white vinegar, crushed garlic, black peppercorns, and bay leaves to a large bowl.
Toss everything together so the chicken is well coated. Cover and marinate in the refrigerator for 4 hours.
Preheat the oven to 375°F (190°C).
Transfer the chicken thighs, skin side down, to a large Dutch oven. Pour the marinade and sauce over the chicken.
Cover the Dutch oven and bake for 30 minutes.
Carefully remove the lid and turn the chicken thighs over.
Spoon some of the sauce over the chicken to glaze the surface.
Return the Dutch oven to the oven, uncovered, and cook for another 30 minutes, or until the chicken is browned, tender, and fully cooked and the sauce has reduced.
Let the chicken rest for a few minutes before serving. Spoon the reduced sauce over the chicken.