Heat water in a sous vide water bath to 133 degrees F (56 degrees C).
Trim any areas of fat left on short ribs; coat thoroughly with garlic and salt. Place ribs into a large, resealable plastic bag. (Use two bags if necessary to leave plenty of room between ribs.) Seal, on low pressure if using a vacuum sealer, removing as much air as possible.
Submerge the bag fully into the water bath and cook, rotating every 12 to 18 hours, for 60 hours. Increase the heat to 144.5 degrees F (62.5 degrees C) and cook an additional 12 hours.
Remove ribs from the water bath; let rest in the bag on a cooling rack placed over a baking sheet until cool enough to handle.
Remove ribs from the bag and drain. Place ribs onto a work surface, turn so bones are facing up, and slice meat between the bones to separate. Cut membrane running along the length of each rib; slide the bone loose from the meat. Trim any excess fat and cut into serving portions. Pat ribs dry with paper towels; return to the cooling rack.
Heat a skillet until smoking hot. Add ribs and brown quickly, 30 to 60 seconds per side.