Pat the beef cubes dry with paper towels. This is crucial for browning. Season with 1 teaspoon salt and all the pepper. Heat the oil in your Dutch oven over medium-high heat until it shimmers. Working in batches to avoid crowding, sear the beef until deeply browned on all sides, about 8-10 minutes per batch. Transfer to a plate. The fond (browned bits) on the bottom is flavor gold - don't scrape it yet.

Reduce heat to medium. Add the onion to the pot and cook, scraping up the browned bits with your wooden spoon, until softened and starting to turn golden at the edges, about 6-8 minutes. Add the garlic and cook until fragrant, about 30 seconds. Stir in the tomato paste and cook for 1 minute to caramelize it slightly.

Return the beef and any accumulated juices to the pot. Add the beef broth, thyme, bay leaves, and Worcestershire. Bring to a boil, then reduce to a bare simmer. Cover partially and cook for 1 hour, stirring occasionally. The beef should be starting to tenderize but not yet fall-apart tender.

Add the carrots, potatoes, and celery. Stir in the remaining 1/2 teaspoon salt. Cover partially and continue simmering until the vegetables are tender and the beef yields easily to a fork, about 45-60 minutes more. The broth should have reduced slightly and thickened from the potato starch. Remove bay leaves before serving.

Let the stew rest off-heat for 10 minutes. This allows the flavors to settle and the broth to thicken slightly. Taste and adjust seasoning. Ladle into bowls with crusty bread for soaking up every drop.