Preheat your oven to 300°F (150°C).
Season the beef short ribs thoroughly on all sides with sea salt and black pepper.
Heat avocado oil in a small Dutch oven or heavy-bottomed oven-safe pot over medium-high heat.
Sear the short ribs for 2-3 minutes per side until a deep golden-brown crust forms, then remove and set aside.
In the same pot, add the diced onions, carrots, and parsnips, sautéing for 5 minutes until the onions are translucent.
Stir in the minced garlic and tomato paste, cooking for 1 minute until fragrant and the paste darkens slightly.
Pour in the beef bone broth, using a wooden spoon to scrape up any browned bits (fond) from the bottom of the pot.
Return the short ribs to the pot, ensuring they are partially submerged, and tuck in the rosemary and thyme sprigs.
Cover with a tight-fitting lid and transfer to the oven to braise for 2.5 to 3 hours, or until the beef is fork-tender.
Remove the herbs before serving the ribs alongside the softened root vegetables and a spoonful of the braising liquid.