Preheat Oven : Set oven to 325°F (165°C).
Season u0026 Sear Short Ribs : Pat short ribs dry and season generously with salt and black pepper. Heat olive oil in a large oven-safe Dutch oven or heavy pot over medium-high heat. Sear short ribs on all sides until deeply browned, about 3–4 minutes per side. Remove ribs and set aside.
Sauté Aromatics : Add sliced onions to the same pot and cook 3–4 minutes until softened. Add minced garlic and sauté 1 minute until fragrant.
Deglaze u0026 Add Liquid : Stir in tomato paste, then pour in apple cider and beef broth. Scrape up any browned bits from the bottom of the pan. Add rosemary, thyme, bay leaves, and apple cider vinegar.
Braise Short Ribs : Return seared short ribs to the pot, ensuring they are partially submerged in the liquid. Cover with a lid and transfer to the oven. Braise for 3–3.5 hours, or until ribs are fork-tender.
Finish Sauce : Remove short ribs from the pot. If desired, place the pot over medium heat on the stove and reduce the braising liquid to a thicker sauce consistency. Adjust seasoning with salt and pepper.
Serve : Plate short ribs, spoon sauce over the top, and garnish with chopped fresh parsley.