Season the short ribs generously with salt and black pepper.
Heat the vegetable oil in a large, oven-safe Dutch oven or heavy-bottomed pot over medium-high heat. Add the short ribs and sear them on all sides until they are browned and have a nice crust. This should take about 4-5 minutes per side. Work in batches if needed to avoid overcrowding the pot. Remove the seared short ribs and set them aside.
In the same pot, add the chopped onion, carrots, celery and fennel. Cook for about 5 to 7 minutes, stirring occasionally, until the vegetables begin to soften.
Add the minced garlic, fennel powder, tomato paste and red vinegar to the pot, and cook for an additional 1-2 minutes, stirring constantly.Return the seared short ribs to the pot. Add the beef broth, bay leaves, thyme, and rosemary. Make sure the liquid covers the short ribs, adding more broth if needed. Bring the mixture to a simmer.
Cover the Dutch oven with a lid and transfer it to the preheated oven. Braise the short ribs for about 2.5 to 3hours, or until the meat is tender and easily pulls away from the bone.
Once the short ribs are done, carefully remove them from the pot and set them aside on a serving platter. Strain the cooking liquid into a bowl, then return the strained liquid to the pot. Bring to a boil and reduce heat to a medium and allow to simmer for about 30 minutes until the liquid has reduced by half. Return the cooked short ribs so they are evenly coated by the sauce.
Serve the braised short ribs over mashed potatoes, celeriac puree or any side of your choice. Spoon some of the rich sauce over the top, and garnish with chopped fresh parsley if desired.
Enjoy your delicious braised short ribs! They should be tender, flavorful, and perfect for a hearty meal.