Place 1 cup of water to the bottom of an instant pot. Place the steam basket into the instant pot and then put the diced up sweet potatoes into the steam basket.
Seal and cook on high pressure for 8 minutes with a quick release.
Remove the steam basket with the potatoes and drain the excess liquid from the instant pot.
Add the potatoes back to the instant pot. Then add in the garlic, milk, butter, salt and pepper.
Beat the potatoes with a hand held mixer on medium speed until all the ingredients are combined and are the desired consistency (be careful not to over mix).
Taste test the mashed sweet potatoes and add in more slat and pepper if needed.