Pat the beef chuck dry with paper towels and season evenly with sea salt and black pepper.
Heat the olive oil in a heavy-bottomed pot or Dutch oven over medium-high heat.
Sear the beef cubes in the pot until a deep brown crust forms on all sides, then remove and set aside.
In the same pot, add the pearl onions, sliced carrots, and halved mushrooms, sautéing for 5 minutes until slightly softened.
Stir in the minced garlic and tomato paste, cooking for 1 minute until the mixture becomes fragrant.
Pour in the red wine to deglaze the pot, using a wooden spoon to scrape up all the flavorful browned bits from the bottom.
Return the beef to the pot and add the beef broth, thyme sprig, and bay leaf.
Bring the liquid to a gentle boil, then reduce heat to low, cover, and simmer for 90 minutes until the beef is fork-tender.
Remove the bay leaf and thyme sprig before serving the stew warm in a shallow bowl.