Place 2 teaspoons dried thyme, 1 ½ teaspoons kosher salt, and 1 teaspoon black pepper in a small bowl and stir to combine.

Dice 1 medium yellow onion (about 1 ½ cups). Mince 3 garlic cloves. Trim off any large pieces of surface fat from 2 ½ to 3 pounds boneless beef chuck roast, then cut into 1 to 1 ½-inch pieces. Sprinkle the salt mixture over the beef until evenly coated.

Heat 1 tablespoon of the vegetable oil in a Dutch oven over medium-high heat until shimmering. Add half of the beef and sear until browned on two sides, 2 to 3 minutes per side. Transfer the beef to a plate. Add the remaining 1 tablespoon vegetable to the pot and repeat searing the remaining beef. Transfer the second batch of beef to the plate.

Add 2 tablespoons unsalted butter and the onion to the Dutch oven. Sauté, scraping the bottom of the pot to loosen any browned bits, until the onions are softened, 3 to 5 minutes. Add the garlic and cook until fragrant, about 30 seconds. Sprinkle in ¼ cup all-purpose flour and stir until it coats the onions, leaves a film on the bottom of the pot, and begins to brown, about 1 minute.

Add 3 cups low-sodium beef broth, 1 tablespoon low-sodium soy sauce, and 1 tablespoon Worcestershire sauce. Whisk until no lumps of flour remain. Return the beef and any accumulated juices to the pot and bring to a boil.

Reduce the heat to maintain a simmer. Cover and cook, stirring every 20 minutes or so, for 1 hour. Uncover and continue cooking until the beef is very tender and the gravy thickens, 45 minutes to 1 hour more.

Pick the leaves from 2 fresh parsley sprigs and coarsely chop if desired. Serve the beef and gravy over mashed potatoes, polenta, cooked egg noodles, or rice, garnished with the parsley.