Push instant pot SAUTE button. Heat oil and add chopped onions. Cook onions for 5 minutes, stiring. Add ground beef and cook for another 3-5 minutes until browned.
Add the rest of ingredients and stir. Close and lock the lid. Pressure cook for 20 minutes. Quick release the pressure once cooked.
Notes
If you are using classic beef bouillon powder, no extra salt needed in the soup.Make sure to rinse barley very well.