Pat the beef chuck dry with paper towels and season evenly with sea salt and black pepper.
Heat the olive oil in a large heavy-bottomed pot over medium-high heat.
Add the beef in a single layer and sear until a deep brown crust forms on all sides, then remove the meat and set aside.
In the same pot, add the halved mushrooms, sliced carrots, and peeled pearl onions, sautéing until the vegetables begin to soften.
Stir in the minced garlic and tomato paste, cooking for one minute until the mixture becomes fragrant.
Pour in the dry red wine to deglaze the pan, using a wooden spoon to scrape up all the flavorful browned bits from the bottom.
Return the seared beef to the pot and pour in the beef broth along with the fresh thyme sprig.
Bring the liquid to a gentle boil, then reduce the heat to low, cover with a tight-fitting lid, and simmer for 90 minutes until the beef is fork-tender.