Season the beef with sea salt and black pepper.
Heat the olive oil in a heavy-bottomed pot over medium-high heat and sear the beef until browned on all sides, then remove and set aside.
In the same pot, add the pearl onions, sliced carrots, and halved mushrooms, sautéing until the vegetables are lightly browned and fragrant.
Stir in the minced garlic and tomato paste, cooking for one minute to deepen the flavor.
Pour in the red wine to deglaze the pan, using a wooden spoon to scrape up any browned bits from the bottom.
Return the beef to the pot and add the bone broth, fresh thyme, and bay leaf.
Bring to a gentle boil, then reduce the heat to low, cover, and simmer for 90 minutes until the beef is fork-tender and the sauce has thickened.
Discard the thyme sprig and bay leaf before serving the stew warm.