1. Turn on the Instant Pot and select the 'Sauté' function. Add a bit of oil and brown the beef stew meat.
2. Add the chopped onion and cook until softened.
3. Add the carrots, celery, potatoes, beef broth, salt, pepper, thyme, and rosemary. Stir well.
4. Close the lid, set the valve to 'Sealing', and select 'Manual' or 'Pressure Cook' for 35 minutes.
5. Once the cooking time is complete, allow the pressure to release naturally for 10 minutes, then quick release any remaining pressure.
6. Open the lid, stir the soup, and serve hot.