Preheat oven:
Heat the oven to 325°F (165°C) and place a rack on the lower middle shelf.Dry and season beef:
Dry the beef with paper towels, then sprinkle with salt and pepper.Sear beef in batches:
In a large Dutch oven or heavy soup pot, warm 1 tablespoon of olive oil over medium-high heat until it shimmers. Working in 2-3 batches, sear the meat for roughly 5 minutes per batch. Add 1 tablespoon of oil for each new batch. Move each batch of browned meat plus its juices to a big bowl and reserve.Cook mushrooms:
Lower the heat to medium, toss in the mushrooms, and cook for 4 minutes.Sauté aromatics:
Mix in the onions, garlic, thyme, parsley, bay leaves, 3 tablespoons of balsamic vinegar, and 1/2 cup of stock; cook for about 5 minutes. Add extra stock as needed to avoid scorching.Add tomato paste:
Stir in the tomato paste and sugar.Bake covered stew:
Return the beef and its collected juices to the pot. Pour in the wine, beef broth, and the cornstarch slurry; bring to a boil. Give it a stir, cover the pot, move it to the oven, and bake for 2 hours.Add vegetables and bake:
Take the pot out of the oven, add the carrots and potatoes. Replace the lid and return to the oven for another hour, or until the vegetables are tender. The meat should be fork-tender and the broth slightly thickened.Adjust seasonings:
Remove the pot from the oven, discard the bay leaves, taste and adjust seasonings. If you like, stir in 1 more tablespoon of balsamic vinegar and 1 more tablespoon of Worcestershire sauce.Garnish and serve:
Sprinkle with fresh parsley and serve the stew hot.