In my humble opinion, Filipino chefs are masters of making and using vinegars. Adobo is a luscious chicken stew that is savory, sweet and rich. The use of cane vinegar to balance out the other flavors is a masterclass in acid use. You can also substitute pork shoulder in this recipe.
Trim the excess skin and large lumps of fat from the chicken.
Marinate the chicken pieces with the soy sauce and smashed garlic for 30 minutes.
Remove the chicken pieces from the marinade (reserve the marinade) and pat dry. Heat the oil in a large, heavy-bottomed pot over medium heat. Once hot, place the chicken legs into the pan, working in batches if necessary, and brown on both sides. When all the pieces are browned, add the bay leaves and cracked peppercorns and cook until aromatic, about 1 minute. Return all the chicken pieces to the pot along with the reserved soy and garlic marinade and add the chicken stock. Bring to a low boil, then reduce to a simmer. Cover and cook until tender, about 40 minutes.
When the chicken is tender, add the sugar and vinegar. Simmer another 10 minutes. Taste and adjust seasoning. The adobo should have a kick of vinegar but taste balanced. If desired, stir in some of the slurry to thicken the liquid into a sauce. Serve over steamed rice with a fresh grind of black pepper.