Cut the beef into 1 ½ -2" chunks. Pat dry, then sprinkle with salt and pepper.
Heat oil in a heavy-based wide pot over high heat
Add Bacon and cook until the bacon is browned (about 5 minutes)
Remove bacon add beef, and brown the pieces well on all sides. Remove and place on a plate until needed.
Lower the heat to medium. If needed, add additional oil.
Add onion and caramelize lightly for about 10 minutes
Add flour and cook stirring one minute, then add tomato paste and cook stirring one more minute.
Add the garlic and the Guinness and cook for about 10 minutes.
Add the Beef stock whisking well until nice and smooth.
Add the vegetables and potatoes, bay leaves, thyme, brown sugar, and Worcestershire.
Add the beef and bacon and any juices that have collected.
Cover and lower the heat, so it is bubbling gently. Let the stew cook covered for 2 hours. At this point, the beef should be pretty tender. Remove the lid and let the stew continue to simmer for an additional 30 minutes. Test the beef and if needed for tenderness cook an additional 30 minutes. The sauce will have reduced and be amazingly flavorful.