Set the Instant Pot to the sauté function. Add olive oil, and when hot, add the beef cubes in batches to avoid overcrowding. Brown the beef on all sides for about 4-5 minutes per batch. Remove and set aside.
In the same pot, add the chopped onion and sauté until translucent, about 3 minutes. Stir in the minced garlic and cook for an additional minute until fragrant.
Add the sliced carrots and diced potatoes to the pot, stirring to combine with the onions and garlic.
Return the browned beef to the pot. Pour in the beef broth and stir in the tomato paste, thyme, rosemary, bay leaf, salt, and pepper.
Seal the Instant Pot lid and ensure the vent is set to sealing. Cook on high pressure for 35 minutes. Once done, allow the pressure to release naturally for about 10 minutes, then perform a quick release for any remaining pressure.
If you prefer a thicker stew, mix cornstarch with 2 tablespoons of cold water to create a slurry. Open the pot and stir in the slurry, then switch to sauté mode for a few more minutes until the stew thickens to your liking.
Stir in the green peas and let them heat through for about 2-3 minutes.
Remove the bay leaf before serving. Ladle the beef stew into bowls and garnish with fresh parsley.
Notes
Optional thickening with cornstarch can be adjusted to preference.