Start by preparing your stew ingredients. Peel and dice your potatoes, onions and carrots. Clean and dice your leeks and celery stalks. Remove the core and dice your tomatoes. Chop your stewing steak into chunks and remove any excess fat.
Place the chopped beef into the Instant Pot inner pot in batches of 3. With each set add salt, pepper, 2tsp of olive oil and a teaspoon of thyme. Place the Instant Pot on sauté and brown the meat on both the top and the bottom.
Remove the meat as you do the batches and have a spare plate to hand for it.
When the beef has been seared the removed from the Instant Pot add the onion. You will still have the flavour from the beef and add an extra teaspoon of olive oil, so it is not dry. Keep cooking the onion until it is soft.
When the onion is soft add the rest of the vegetables and give it a good stir. Then add your seared beef back into the Instant Pot.
Add the seasoning along with the Guinness and the beef stock.
Place the lid on your Instant Pot, set the valve to sealing, cancel sauté and cook for 45 minutes on the meat and stew setting.
When cooked remove any excess liquid and stir.
Serve with bread or dumplings.