Turn your Instant Pot to Sauté mode. Add olive oil and beef cubes. Brown the meat on all sides (about 4–5 minutes). Work in batches if necessary to avoid overcrowding.
Stir in the chopped onion and garlic. Sauté for 2 more minutes until fragrant.
Press Cancel. Add tomato paste, and stir to coat. Then add the carrots, potatoes, beef broth, salt, pepper, and herbs if using. Mix well.
Close the lid and set the valve to Sealing. Cook on High Pressure for 25 minutes.
Allow the Instant Pot to release pressure naturally for 10 minutes, then quick release the remaining pressure.
If you’d like a thicker stew, mix the cornstarch and water into a slurry. Turn on Sauté mode and stir the slurry into the stew. Let it cook for 2–3 minutes until thickened.