Pat the beef stew meat 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.
Add the beef to the pot and sear until deeply browned on all sides, then remove the meat and set aside.
In the same pot, add the pearl onions, sliced carrots, and halved mushrooms, sautéing for 5 minutes until they begin to soften.
Stir in the minced garlic and tomato paste, cooking for 1 minute until fragrant.
Pour in the dry red wine to deglaze the pot, using a wooden spoon to scrape up any browned bits from the bottom.
Add the beef broth, fresh thyme, and bay leaf, then return the beef and any accumulated juices to the pot.
Bring the liquid to a gentle boil, then reduce the heat to low, cover, and simmer for 60 to 90 minutes until the beef is fork-tender.
Remove the thyme sprig and bay leaf before serving warm in a shallow bowl.