Season the beef roast on all sides with salt and pepper and set aside.
Set your instant pot to the sauté function and add in the oil.
Sear the beef on all sides until it is well browned. Remove the beef and set aside.
In the instant pot, while still on the sauté function, add in the onions and garlic and sauté for 6-8 minutes.
Add the beef stock in, season with salt and pepper, and add back in the browned pot roast.
Close the lid and seal the instant pot valve and set to pressure cook for 20 minutes per pound.
Once it is done pressure cooking, un-seal the pressure valve and let stand for 10 minutes.
Remove the lid and stir in the balsamic vinegar.
Serve with the cooked onions and blue cheese crumbles.
