Heat the oil in a large pan. Dust the chunks of beef in the flour and fry the beef for 7-8 minutes until golden brown all over (you can do this in two batches if your pan isn't big enough). Add the onions and cook for a further 5 minutes. Stir in the garlic. Add in the Guinness, stock, tomato puree, bay leaves, salt, pepper, potatoes and carrots. Bring to a gentle boil then transfer to the slow cooker. Cook on high for 4-5 hours or low for 6-7 hours (alternatively you could put a lid on the pan and cook in the oven for 3 hours at 160c/325f).
Test for seasoning and add a little more salt and pepper if required.
Cut the lids off 6 bread cobs/boules. Use your hands to hollow most of the bread from the inside. Make sure you don’t make any holes that the stew would leak out of
Spoon the stew out into the bread cobs (being careful not to break up the potato as it will be very tender by now), top with a few leaves of parsley and serve with the lid of the bread cob.