Season the diced beef with salt and pepper.
Heat 1 ½ tablespoons olive oil in a large casserole pot over high heat. Add half of the beef. Brown the beef for around 4 minutes, stirring a few times. Remove the cooked beef and repeat with the remaining beef, adding more olive oil if required.
Turn the heat down to medium-high. Add 1 tablespoon of oil, onion, garlic, carrot and celery, and cook for 3 minutes until browned.
Add the tomato paste and stir for 30 seconds.
Sprinkle in the flour and mix.
Add the red wine, beef stock, sugar, worcestershire sauce, bay leaf and thyme.
Add the cooked beef (including any juice) and potatoes. (Make sure the liquid covers everything; if not, add some water.)
Bring to a simmer, then turn the heat to low so it's simmering gently.
Put the lid on and cook for 1 hour 45 minutes, or until beef is tender with a fork.
Remove the lid and allow to simmer for a further 30 minutes to reduce the liquid.
Season with salt & pepper and serve with some crusty bread.