3large potatoespeeled and chopped into large chunks
Set the Instant Pot to the saute function.
Add a few tablespoons of oil and add the beef in batches. Brown well on all sides then remove and set aside.
Add the onions, carrots and celery. Saute for 5 minutes then add the garlic, herbs and tomato paste. Cook for 1-2 minutes.
Add the beef, stock and Guinness. Close the lid and move the valve to "sealing". Cook on the meat setting for 30 minutes.
After 30 minutes, quick release the pressure and add the potatoes. Seal the lid again and cook on high pressure for 10 minutes.
Allow the pressure to release then set to the saute function. Allow the stew to simmer then stir in the flour and water mixture. Allow to simmer for 5 minutes until the stew has thickened. Season to taste and serve.