Remove the ribs from the marinade and pat dry with paper towels. Reserve all the marinade.
Heat the oil in a large Dutch oven or heavy-bottomed pot over medium-high heat. Working in batches to avoid crowding, sear the ribs until browned on all sides, about 2-3 minutes per side. Set browned ribs aside.
Return all ribs to the pot. Pour the reserved marinade over the ribs.
Bring to a boil, then reduce heat to low. Cover and simmer gently for 1½ to 2 hours, turning the ribs occasionally, until the meat is very tender and pulls easily from the bone.
Remove the lid and increase the heat to medium. Simmer uncovered for 20-30 minutes, turning the ribs occasionally, until the braising liquid reduces to a thick, glossy sauce that coats the ribs.
For caramelized edges, transfer the ribs to a foil-lined sheet pan, brush generously with the reduced sauce, and broil on high for 3-5 minutes, watching carefully to avoid burning.
Vinegar is key. Traditional Filipino adobo uses cane vinegar (sukang maasim). White distilled vinegar or apple cider vinegar are acceptable substitutes. Do not stir the pot for the first 10 minutes of braising — this allows the vinegar's sharp acidity to cook off and mellow.
Low and slow. Keep the braise at a gentle simmer, not a rolling boil, to keep the meat from toughening.
Make ahead. Adobo tastes even better the next day. Refrigerate the ribs in the sauce overnight and reheat gently before serving.