Generously season the short ribs with salt. Reserve.
Prepare the grill for indirect grilling at 350°F. Preheat the Dutch oven in the direct zone. (For a Kalamazoo Hybrid Fire Grill, place the Dutch oven on the grill grate in the center of the grill. Preheat the grill with the lid closed and all main burners on HIGH for 15 minutes.)
Heat the canola oil in the Dutch oven, then brown the short ribs on all sides, about 8 minutes. Remove the ribs from the Dutch oven and reserve. Brown the onion and garlic in the same oil until slightly translucent. Deglaze the Dutch oven with the white wine. Stir in the chicken stock and rosemary. Add the short ribs back into the Dutch oven, cover, and place it in the indirect zone of the grill. (For a Kalamazoo K750 Series Hybrid Fire Grill, turn the middle burner and left burner OFF. With one main burner running on HIGH, the air temperature in the indirect zone will be 350°F.)
Braise the short ribs in the indirect zone at 350°F with the grill lid closed. Rotate the Dutch oven every 30 minutes for even cooking. Braise the ribs until tender, about 2 hours.
Remove the ribs from the braising liquid, and brown them on all sides on the hottest area of the grill grate for about 5 minutes. Reserve.
Add the butter to the braising liquid. Use an immersion blender to create a velvety sauce.
Plate the ribs and dress with the sauce. We served these ribs with grilled ramps and white rice.