Preheat oven to 325 degrees. Heat oil in a 3.5 quart or larger cast iron casserole skillet. Add the onions and carrots and cook over low heat, stirring occasionally until onions are softened, about 7 minutes.
Remove the onions and carrots form the pan with a slotted spoon and set aside.
Pour the flour into a large zipper top bag then add the salt and pepper. Add the beef chunks to the bag and shake well to coat.
Carefully add half of the seasoned beef to the pan. Cook, stirring frequently until browned all over.
Remove from the pan and repeat with the second half of the beef. Once browned, add the Guinness to the pan scraping the bottom with a wooden spoon to remove all of the cooked bits. (deglaze the pan)
Return the beef, carrots and onions to the pan and add the bay leaves and thyme. Stir to combine.
Bring to a boil, cover and cook in the oven for 1 hour and 45 minutes.
Herb Dumplings
Sift the flour, baking powder and salt into a large bowl.
Stir in the beef tallow and parsley.
Add enough water to make a soft dough. Shape into six small balls.
Place the dough balls on top of the cooked beef mixture and bake for an additional 30 minutes.
Remove and discard the bay leaves. Serve sprinkled with chopped parsley.
Notes
If fresh thyme is not available, substitute 1 teaspoon of dried thyme.
Substitute suet or shortening for the beef tallow if preferred.
If you must omit the Guinness, substitute beef stock and add 2 tablespoons Worcestershire sauce.