Preheat your oven to 325°F.
Season the beef short ribs generously with salt and pepper.
In a heavy, oven-safe pot or Dutch oven, heat the olive oil over medium-high heat. Sear the short ribs on all sides until they develop a deep brown crust.
Remove the ribs temporarily and add the sliced red onion and garlic to the pot, sautéing until fragrant.
Return the ribs to the pot and add a couple of sprigs of fresh rosemary. If desired, a splash of water or broth can be added to deglaze the pan.
Cover the pot and transfer it to the oven. Allow the short ribs to braise slowly for about 2 to 2.5 hours until they are tender.
While the ribs are braising, prepare the vegetables: on a baking sheet, toss the chopped carrots, parsnips, and additional rosemary with a pinch of salt and pepper.
Once the ribs are nearly finished, increase the oven temperature to 400°F. Roast the vegetables for about 20-25 minutes, or until they are caramelized and tender.
Plate the tender short ribs with a generous serving of the roasted root vegetables. Drizzle any remaining braising juices over the top for added flavor.
Serve warm and enjoy this hearty, balanced dish.