Clean and dry your potatoes. You don’t need to cut or peel them.
Separate the garlic cloves and peel the skins off.
Add the potatoes to the slow cooker along with the garlic.
Place the lid on the slow cooker.
Set the slow cooker to HIGH for 4 hours.
Open the lid, and with a potato masher start breaking up the potatoes.
Add in all of the butter and ½ cup of the milk to start.
Begin whipping the potatoes with a hand mixer. Add more milk as needed to get your desired consistency.
Try not to overwhip the potatoes as they could get gummy. When it appears they have enough liquid, whip them for about 30-60 seconds.
You can keep the potatoes set to warm for 2 hours.