01 - Preheat the oven to 325°F (160°C).
02 - Pat beef short ribs dry and season all sides generously with kosher salt and black pepper.
03 - Heat olive oil in a large Dutch oven over medium-high heat. Working in batches, sear the short ribs on all sides, about 2–3 minutes per side, then transfer to a plate.
04 - Reduce heat to medium. Add onions, carrots, and celery to the pot and cook, stirring occasionally, until softened and golden, 6–8 minutes.
05 - Stir in garlic and tomato paste; cook for 1 minute until fragrant.
06 - Pour in apple cider, scraping up browned bits from the bottom. Add beef broth and apple cider vinegar.
07 - Return short ribs and any accumulated juices to the pot. Add bay leaves, thyme, and rosemary.
08 - Bring to a gentle simmer. Cover, transfer to preheated oven, and braise for 2.5 hours or until meat is very tender and nearly falling off the bone.
09 - Remove pot from oven. Skim excess fat from surface. Discard bay leaves and herb stems. Serve short ribs with braised vegetables and pan juices over mashed potatoes or creamy polenta if desired.