Set the Instant Pot to the "saute" function. While the Instant Pot is heating. Open the package of beef cubes and sprinkle them with salt and pepper.
Place the flour in a zip-style plastic bag. Add half of the beef cubes to the flour, Seal the bag and shake to coat the beef with the flour. Set aside until the Instant Pot registers "hot".
When the Instant Pot indicates that it is hot, add 2 tablespoons of cooking oil to the bottom of the liner. Place the floured beef cubes in the oil. Cook until browned on one side, about 3 minutes. Turn the cubes over and continue to brown. Add additional oil, if necessary. Sometimes the beef is lean and sometimes it is a bit fatty. Leaner beef will likely need additional oil in order to brown well.
When browned, remove beef cubes to a plate or other appropriate container. The beef will not be cooked through. Repeat the flouring and browning process with the other half of the beef.
Leave the second batch of beef in the pot. Add the beef stock, Worcestershire sauce, and rosemary or thyme. Stir with a non-abrasive spoon (such as silicone or wood) to loosen the browned bits from the bottom of the pot. Don't use a metal utensil because it may scratch the liner.
Add the remaining beef back to the pot. Wipe the top of the pot to make certain that it is clean. If the pot is dirty, a secure seal will not form between the lid and the pot. Place the lid on the pot and lock it in place. Make sure that the steam release knob is in the closed position. Set the pot to pressure cook (manual) for 20 minutes on HIGH. Allow the pressure to release naturally for 10 minutes, then set release valve to quick release.
Open the pot with the top of the lid towards you. Opening it this way will protect you from the rush of steam from the pot. Add the carrots, potatoes, onions and garlic. Give everything a couple of stirs.
Replace the lid, lock it in place and turn the steam release knob to the closed position. Set the pot to pressure cook for 10 minutes on LOW. Allow the pressure to release naturally for 10 minutes, then quick release to vent the remaining pressure. When pressure is fully released, open the pot as before.
Stir the stew. It should have thickened during cooking, but if you desire it to be thicker, do the following. Whisk together 1/2 cup cool water and 3 tablespoons white flour to form a smooth slurry. Press the saute button on the IP to keep the stew boiling. While stirring the stew, add the slurry a little at a time until the desired consistency is reached. Serve as desired. This is always a good meal with a salad or crusty bread.