In Instant Pot, add onion, carrot, celery, 2 garlic cloves, potatoes and beef as you are cutting them. Then add tomato paste, beef stock, oregano, thyme, salt, pepper, bay leaves and peppercorns. No need to stir, just flatten tomato paste with a spoon.
Close the lid, set pressure vent to Sealing and press Pressure Cook on High for 30 minutes. Display will say ON, Instant Pot will take about 20 minutes to come to pressure, you will see a bit of steam coming out from a valve, then float valve will rise and countdown from 30 minutes will begin.
When display says OFF, stew is ready. Now your Instant Pot needs to bring pressure down before you can open it, which will be indicated by a dropped down float valve. You can let it do it on its own which will take about 15-20 minutes - Natural Release. OR you can do Quick Release by turning pressure valve to Venting position, which takes 2-3 minutes. I recommend doing so outside to avoid countertop mess and house smelling like stew for days.
Open the lid, add peas, remaining 2 cloves of garlic and dill. Stir.
To thicken beef stew: Switch Instant Pot to Saute. In a small bowl, whisk cold water with cornstarch, add to the pot and stir gently. Cook for a few minutes until thickened.
Serve hot with crusty bread.
Video
Notes
Store: Refrigerate in an airtight container or inner Instant Pot pot with a fitting glass lid for up to 5 days.
Freeze: I have not tried to freeze the stew as there are never leftovers and I question how well potatoes would thaw.
If you made a slurry beforehand, make sure to stir it right before adding to the pot. Cornstarch settles fast.
I don't recommend to use dried dill. If you are not a fan of dill or don't have any on hand, add fresh parsley.