Heat olive oil in heavy large pot over medium-high heat. Lightly salt the beef pieces. Working in batches if necessary, add the beef (do not crowd the pan, or the meat will steam and not brown) and cook, without stirring, until nicely browned on one side, then use tongs to turn the pieces over. Continue to cook in this manner until all sides are browned, about 5 minutes.
Add garlic and sauté 1 minute. Add beef stock, Guinness, red wine, tomato paste, sugar, basil, thyme, Worcestershire sauce and bay leaves. Stir to combine.
Bring mixture to boil. Reduce heat to medium-low, then cover and simmer 1 hour, stirring occasionally.
While the meat and stock is simmering, melt butter in another large pot over medium heat. Add onion, carrots and potatoes. Sauté the vegetables until golden, about 20 minutes.
After the first hour, add vegetables to beef stew. Simmer uncovered until vegetables and beef are tender, about 20 minutes. Discard bay leaves. Sprinkle with parsley and serve.