Preheat the oven to 300˚F.
Set a heavy Dutch oven over medium-high heat, add a drizzle of oil and brown the ribs on all sides, sprinkling them with salt.
Add the onion and garlic to the pan and cook for a few minutes, until they start to soften.
Add the wine and stock—enough to come about halfway up the ribs.
Cover and cook for 3 hours, or until the meat is very tender. (Alternatively, transfer everything to a slow cooker and cook on low for 6-8 hours.)
Serve over mashed potatoes, with the extra sauce.