Turn a 6.5-quart Instant pot onto saute function. Add 2 tablespoons of vegetable oil. When the display reads "hot". Add the beef in batches, in a single layer, and brown. Remove to a plate. Repeat the process with the remaining oil as needed and beef.
Add the onions (1 ½ cups) and garlic (4 cloves) to the Instant pot and saute, until soft, about 3 minutes. Add tomato paste (2 tablespoons), stirring constantly, and continue to saute for 1 minute.
Add beef broth (3 cups) stirring, gently scraping the bottom of the pot with a wooden spoon to loosen all brown bits on the bottom of the pan (do not skip or the burn light may turn on).
Add dissolved Better Than Bouillon (1 tablespoon), Worcestershire sauce (2 tablespoons), Italian seasoning (1 teaspoon), thyme (1/2 teaspoon), bay leaf (1), salt (2 ¼ teaspoons), and pepper (1 teaspoon) and stir to combine. Add in potatoes (2 cups), carrots (2 cups), and browned beef.
Lock the lid and set the valve to seal. Set the function to "manual mode-high pressure" for 35 minutes. The instant pot will start on its own.
Switch the valve to the "venting" position to quick release for 10 minutes.
Carefully remove the lid (there will likely still be some remaining steam). Remove and discard bay leaf. Gently stir in the peas (1 cup) and cornstarch slurry (3 tablespoons). Turn off the heat and allow it to sit for 3-4 minutes to thicken before serving.