Gently pull the roast apart at the seams, trim any excess fat and cut into 1 inch pieces. Season with salt and pepper.
Turn the instant pot to the saute function (or if slow cooking, heat a skillet over medium heat) and heat the oil until It shimmers. Add the onion and salt and cook until the onion softens but doesn’t brown about 3 minutes. If slow cooking, you can do this in a skillet and transfer to the slow cooker later.
Stir in flour, tomato paste, and thyme and cook for about a minute.
Whisk in broth and soy sauce, scraping any browned bits from the bottom (if you’re using a skillet, only add enough of the broth to deglaze and add the rest in the slow cooker).
Add beef, carrots, and potatoes.
Put the lid on the pressure cooker and cook on high pressure for 25 minutes. Allow the pressure to naturally release for about 10 minutes, then quick-release any remaining pressure.
Note: If slow cooking, transfer to the slow cooker and cook for 7 to 8 hours.
Stir in peas and let sit until heated through.
Taste and adjust seasoning with salt and pepper.