Heat the oven to 350°F.

Fill a medium pot with 6 cups of water and bring to a boil (do not salt). While the water is coming to a boil, trim the root ends from the pearl onions.

Add the trimmed onions to the boiling water and blanch for 2 minutes. Remove from heat, drain in a colander, and plunge into an ice bath. Allow to sit in the ice bath for a few minutes, then drain. Peel the onions by gently squeezing until they pop out of the tough outer skin.

Divide the beef into 2” cubes, then pat dry with paper towels. Season generously with salt and pepper.

Heat a 6-quart dutch oven over medium high heat. Add the olive oil and heat until it shimmers. Add the beef and arrange in a single layer, with a bit of space between each piece. Sear undisturbed until a dark, golden brown crust forms, 4-5 minutes. Turn the pieces and sear on at least one more side. Remove using tongs, set aside onto a plate, and repeat with the remaining chuck roast pieces.

Add the bacon to the pot and cook, stirring occasionally, until the fat renders and the edges start to brown, about 5 minutes. Push the bacon to the outer edges of the pot and add the onions. Cook, stirring occasionally, until the onions are soft and starting to brown in spots, 8-10 minutes. Add the garlic and sauté with the onions, stirring frequently, until fragrant, about 1 minute.

Pour in the balsamic vinegar to deglaze the pot; cook, stirring up the browned bits from the bottom of the pot, until the vinegar stops bubbling and is mostly evaporated, and the bottom of the pot is clean, 2-3 minutes.

Return the seared beef to the dutch oven. Pour in the wine plus enough broth to barely cover the beef, then give the contents a good stir. Add the bay leaf, fresh thyme, ½ teaspoon salt, and ½ teaspoon ground pepper. Increase the heat to high and bring the liquid to a simmer. Cover the pot, turn off the burner, and transfer to the oven. Braise for 2 hours.

Remove the pot from the oven and place onto the stove. In a small measuring cup, whisk together the cornstarch and one cup of beef broth to create a slurry. Pour the slurry into the stew, then add the chopped potatoes, carrots, and celery. Give the stew a good stir, and again heat over high until the liquid comes to a simmer. Cover, and return the stew to the oven to continue braising. Cook an additional 1-1.5 hours, or until the beef is falling apart and the vegetables are tender.

Once the stew is ready, increase the oven temperature to 450°F and remove the lid. Cook 15 minutes more at the higher temperature to caramelize the top of the stew and thicken the gravy.

Remove the dutch oven from the stove. Fish out the bay leaf and thyme sprig using tongs. Ladle into stew bowls and garnish with chopped fresh parsley if desired. Serve immediately. This stew keeps in the fridge in a tightly sealed container for up to 5 days, and is even better the next day.