1 medium onion, halved and thinly sliced (1 1/2 cups)
1 head of garlic, cloves separated, flattened, peeled, and roughly chopped. (about 6 tablespoons chopped)
1 tablespoon plus 1 teaspoon Thai fish sauce or Filipino fish sauce
1 teaspoon freshly ground black pepper
2 dried bay leaves
Marinate Chicken: Put chicken in a non-reactive bowl or casserole. Combine the vinegar and 1 tablespoon of the chopped garlic. Pour over chicken and turn to coat. Marinate in the fridge or in a cool place for 30 minutes. Remove chicken from the marinade, allowing excess to drip back into the bowl and transfer chicken to a clean plate. Reserve the marinade.
Brown Chicken & Aromatics: Heat oil over medium heat in a large dutch oven or another heavy pot with a lid. Pat chicken lightly with a paper towel to dry. Brown in batches (4-5 pieces at a time), starting skin side down for 3-4 minutes. Turn and brown for just a minute on the other side. Transfer to a clean plate. Repeat with all the chicken. Pour out all but 2 tablespoons fat from the pot. (hint: It’s easier if you pour it all out, into a small bowl or coffee cup, and then add back the 2 tablespoons) Set the heat to medium-low, add onions and the rest of the garlic to the pot and sauté, stirring occasionally, for about 10 minutes, until the onions are softened.
Simmer Chicken: Return the chicken to the pot along with any accumulated juices, vinegar-garlic marinade, soy sauce, fish sauce, black pepper, bay leaves and 1/4 cup of water. Toss chicken with onions and sauce to coat. Bring to a boil. Lower to a simmer. Cover and cook at a low steady simmer for 30 minutes. The next step is optional. If you skip it, keep simmering the chicken for 30 minutes longer (see step 5)
Optional step: De-fat the sauce before continuing I don’t like a lot of unnecessary fat in my food so this is a step I often do when I’m cooking a soup or stew, though it’s not required. Turn off heat for 5 minutes to let the fat rise to the surface. Use a teaspoon to carefully skim off several spoonfuls of fat. The fat will be clear vs the sauce, which is brown. No need to get all the fat. You can always skim more when the dish is done, if you like.
Finish: Return the pot to a simmer. Toss chicken to coat with sauce. Cover and simmer gently for 30 more minutes, or until the chicken is tender and the sauce is a rich brown color. Serve over rice.