Place potatoes and carrots in the inner pot of the pressure cooker. Add the broth, vinegar salt, pepper, garlic powder, and onion powder and stir to combine.
Place the lid on the Instant Pot and be sure the vent knob is pushed towards sealed. Set cook time for 10 minutes on high pressure by hitting manual or pressure cook and adjusting it to read "10" by using the +/- buttons.
Once the cooking time has elapsed, let the pressure release naturally for at least 10-15 minutes.
Once the pressure has been released, hit cancel on the Instant Pot and then turn to the saute function. Meanwhile, whisk together the milk and cornstarch until very well combined in a glass measuring cup.
Once the potato soup is bubbling slightly, pour the milk mixture into the inner pot, stirring well to combine.
Let potato soup simmer, stirring constantly, until the soup thickens. This will only take a few minutes. Once thickened, hit cancel on the Instant Pot.
Ladle out the soup into individual bowls and top as desired with shredded cheese, crumbled cooked bacon, and/or chives.
Feel free to use peeled or unpeeled russet potatoes.
If you like your soup on the thinner side, use 3 cups of stock.
Feel free to use flour in place of cornstarch.
I recommend adding in 1 teaspoon plain vinegar before cook time to help heighten the flavors of this Instant Pot Potato Soup.
If you would like to use fresh onions and garlic, feel free to use ¼ cup of chopped onion and 1 clove of minced garlic.