Turn your Instant Pot on and select the ‘Saute’ function on high.
When the Instant Pot is hot, add in olive oil and meatballs. Cook meatballs until all sides are slightly browned, about 10 minutes. They do not need to be cooked all the way as they will continue to cook during the pressure cooking phase. NOTE: be sure to move the meatballs regularly to ensure they do not stick to the bottom of your Instant Pot. Doing so will ensure you do not receive the ‘Burn’ notification.
Once the meatballs are evenly browned, remove the meatballs and set aside for now.
While still on the ‘Saute’ function, add in butter and onions and saute until onions are slightly browned and caramelized. Add minced garlic and continue to saute for an additional minute or two.
Add in beef stock and scrape the bottom of the pot gently to deglaze.
Add in salt, garlic pepper and red wine (optional) and stir contents.
Select the ‘Cancel’ function to reset the cooking function.
Add meatballs back into your Instant Pot and select the ‘Pressure Cook’ or ‘Manual’function on high.
Secure the Instant Pot lid and pressure cook for 10 minutes.
Once the timer beeps, allow the pressure to naturally release for 5 minutes then quick release all remaining pressure.
Carefully remove the meatballs from the Instant Pot once again and set aside until gravy is thickened.
While on ‘warming’, add cornstarch slurry to the Instant Pot and stir until contents are well combined.
Taste and add any additional seasoning needed.
Once gravy has thickened to your liking, add the meatballs back into the Instant Pot and stir until meatballs are covered in gravy.
Serve over mashed cauliflower or mashed potatoes.