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.