Spread beef out on a plate and season with 2 tsp salt and 1 tsp pepper. In a large heavy-bottomed pot, heat 1 tablespoon of the olive oil over medium-high heat until shimmering. Brown the meat in small batches (I did it in 3), being sure not to crowd the pot. (This allows the meat to develop a golden brown crust, which is important). For each batch, add one additional tablespoon of olive oil. Transfer the meat to a large plate and set aside.
Add the onions, garlic, sofrito and balsamic vinegar; cook, stirring with and scraping the brown bits from bottom of the pan, for about 3 minutes, until the liquid is reduced. Add the tomato paste and cook for a minute more. Add the beef with its juices back to the pan and sprinkle with the flour. Stir until the flour is dissolved, 1 to 2 minutes. Add the wine, and let the wine reduce by half, then add the beef broth, water, bay leaf, and thyme. Bring to a boil, cover the pot with a lid and reduce to a simmer.
After 45-60 minutes, add the potatoes and carrots. Simmer for another 20-25 minutes until the beef and vegetables are tender. Discard the bay leaf, taste and adjust seasoning.
