Open up Wonderbag, puff up the pockets of insulation and leave open to air.
In the large pot you plan to use, cook the chopped bacon and set aside.
Add a little olive oil to the pan, followed by the beef, salt and pepper. Brown and set aside.
Add onions, garlic and celery to the pot and fry for 5min.
Add the tomato paste and sugar, and mix, followed by the Guinness and beef stock. Simmer.
Add the red wine and sherry, as well as the thyme sprigs. Simmer.
Put the cooked bacon and browned beef back into the pot.
Bring to the boil and cook for 20min with the lid on.
Place your pot in the Wonderbag (we placed it on a cast iron trivet underneath the pot to prevent it burning our Wonderbag) , place the insulating cushion on top and close it all up so that it looks like this.
Leave sealed for 3 hours.
After 3 hours open up and lift lid. If the liquid needs thickening, make a slurry with the cornflour and water, add to the pot and mix well.
Serve with mashed potato, rice or warm, crusty Irish soda bread.