Preheat the oven to 350 degrees . Place the meat in a large bowl and season with salt and pepper. Add the flour and toss to coat. In a large Dutch oven or ovenproof pot, heat 2 tablespoons olive oil and 1 tablespoon butter over medium-high heat until the butter stops foaming. Add a quarter of the meat to the Dutch oven and brown, about 6 minutes; transfer with a slotted spoon to a platter. Cook the remaining meat in 3 batches, adding 1 more tablespoon olive oil and 1/2 tablespoon butter to the Dutch oven for each batch.
Add the onion, garlic and thyme to the Dutch oven and cook until the onion has softened, about 5 minutes. Stir in the browned beef, Worcestershire sauce, balsamic vinegar, brown sugar, cocoa powder, paprika, cinnamon, bay leaf and beef broth and bring to a simmer. Cover, transfer to the oven and cook until the beef is tender, about 1 1/2 hours.
About 20 minutes before the stew is done, bring a large pot of salted water to a boil and cook the egg noodles until al dente, about 7 minutes. Drain and toss with the remaining 2 1/2 tablespoons butter. Serve the stew over the noodles.