Set the Instant Pot to 'Sauté' mode. Add the olive oil and let it heat up.
Once the oil is hot, add the chopped onion and sauté until it becomes translucent (about 3-4 minutes).
Add the minced garlic and cook for another minute until fragrant.
Stir in the beef chunks and season with salt and pepper. Sauté until the beef is browned on all sides, about 5-7 minutes.
Add the sliced carrots and diced potatoes to the pot.
Pour in the beef broth, and stir in the tomato paste, dried thyme, dried rosemary, and Worcestershire sauce, if using.
Add the bay leaf on top and give everything a final stir to combine.
Close the lid of the Instant Pot and set it to 'Manual' high pressure for 35 minutes.
After the cooking time, allow for a natural release for 10 minutes, then manually release any remaining pressure.
Carefully remove the bay leaf. If you want a thicker gravy, mix the cornstarch with a little water to create a slurry and stir it into the stew. Set to 'Sauté' mode for a few minutes until the stew thickens.
Taste and adjust seasoning with additional salt and pepper if needed.
Ladle the beef stew into bowls and garnish with freshly chopped parsley before serving.