Pat the beef stew meat dry with paper towels and season with sea salt and black pepper.
Heat the olive oil in a heavy-bottomed pot or Dutch oven over medium-high heat.
Add the beef in a single layer and sear until deeply browned on all sides, then remove and set aside.
In the same pot, add the pearl onions and mushrooms, sautéing for 3-4 minutes until they begin to soften.
Stir in the minced garlic and tomato paste, cooking for 1 minute until fragrant.
Pour in the beef bone broth, using a wooden spoon to scrape up any browned bits from the bottom of the pot.
Return the beef to the pot and add the sliced carrots, parsnips, thyme sprig, and bay leaf.
Bring the liquid to a gentle boil, then reduce heat to low, cover, and simmer for 60-90 minutes until the beef is fork-tender.
Remove the bay leaf and thyme sprig before serving in a shallow bowl.