Preheat your oven to 325 degrees Fahrenheit. Season the beef short ribs generously on all sides with salt and black pepper. In a large heavy bottomed pot or Dutch oven, heat the vegetable oil over medium high heat. Sear the ribs in batches, making sure not to crowd the pan, until they are deeply browned on all sides. This should take about 3 to 4 minutes per side. Remove the ribs and set them aside on a plate.
In the same pot, reduce the heat to medium. Add the diced onion, carrots, and celery. Cook the vegetables for about 5 to 7 minutes until the onions are translucent and the vegetables have softened slightly. Add the minced garlic and cook for just one more minute until it becomes fragrant, being careful not to let it burn.
Pour in the apple cider and use a wooden spoon to scrape up all the browned bits from the bottom of the pot. These bits, known as fond, hold a tremendous amount of flavor. Bring the liquid to a simmer and let it reduce by about a third, which usually takes about 5 minutes.
Stir in the beef broth and the apple cider vinegar. Place the seared short ribs back into the pot, ensuring they are mostly submerged in the liquid. Tuck the thyme, rosemary, and bay leaves into the spaces between the ribs. Bring the entire mixture back to a gentle simmer on the stove.
Cover the pot with a tight fitting lid and transfer it to the preheated oven. Bake for 3 to 3.5 hours. The ribs are done when the meat is incredibly tender and literally falling away from the bone. Check the pot occasionally to ensure there is still plenty of liquid, adding a splash more broth if needed.
Once finished, remove the pot from the oven. Carefully lift the ribs out of the liquid and place them on a serving platter. Discard the bay leaves and herb stems. If the sauce is too thin, you can simmer it on the stovetop for a few minutes to thicken it before spooning it over the ribs.
