In a large bowl, combine the vinegar, soy sauce, garlic, peppercorns, bay leaves and brown sugar. Add the chicken and toss to coat. Cover the bowl and place it in the refrigerator for at least one hour, and up to three.
In a large skillet over medium-high heat, warm the canola oil until glistening. Add the chicken (letting as much marinade drip off as possible) to the pan. Brown the chicken thighs on both sides, about 6 minutes total.
Add the remaining marinade to the skillet and bring to a boil. Lower the heat to medium to maintain a heavy simmer for 10 minutes. Flip the chicken thighs. Simmer, stirring occasionally, until the sauce has reduced by half and is beginning to thicken, about 10 more minutes. When the chicken thigh reads 165°F on an instant-read thermometer, remove from the heat.
Serve the chicken thighs over cooked rice, sprinkled with green onions.