Prep the Beef: Pat beef cubes dry with paper towels; season with salt and pepper on all sides. (Optional) Dredge the beef lightly with flour to help brown and thicken the stew later.

Sauté and Brown for Maximum Flavor: Set Instant Pot to Sauté mode. Once hot, add oil. Add beef in batches, browning thoroughly to develop a deep crust; transfer browned beef to a plate. Add diced onion and minced garlic to the pot. Sauté until softened, about 2–3 minutes.

Build the Broth: Add tomato paste; cook, stirring, until darkened, about 1 minute. Stir in thyme and any dried herbs. Deglaze the pot with a splash of beef broth. Return beef and accumulated juices. Add carrots and potatoes. Pour in remaining beef broth and Worcestershire sauce. Add bay leaf and a pinch more salt and pepper if needed.

Pressure Cook: Secure the Instant Pot lid and set the pressure valve to Sealing. Cook on Manual/High Pressure for 25–35 minutes. Allow a natural pressure release for at least 10 minutes after cooking.

Thicken the Stew: Mix 1–2 tablespoons cornstarch with equal cold water to create a slurry. Stir into hot stew. Set Instant Pot to Sauté and simmer for 2–3 minutes, stirring gently, until thickened.

Final Touches and Serving: Stir in frozen peas and let them warm in the residual heat. Taste; adjust seasoning with additional salt, pepper, or Worcestershire sauce as desired. Serve hot, garnished with fresh parsley.