Preheat oven to 350.
Heat the oil in a dutch oven over medium high heat.
Mix together flour salt and pepper.
Dredge meat in the flour mixture in small batches and brown in the oil.
Remove the browned beef and set aside.
Add the onion to the pan and cook until golden (about 5 minutes).
Add Guinness and garlic and scrape the browned bits from bottom of pan.
Add the browned beef and the remainder of dredging flour to the dutch oven and bring to a simmer.
Add in the beef stock, tomato paste, brown sugar, thyme, and Worcestershire sauce. Stir well to combine.
Place the lid on the dutch oven and place in the oven for about 2 hours or until the meat is fork tender.
Add in the carrots and return to the oven for 1 hour.
Add in the potatoes and return to oven for 1 hour or until the potatoes are cooked through.