Wash and peel the potatoes, then dice them into one-inch cubes. Rinse the diced potatoes with cool water in a colander to remove the excess starch.
Add the cubed potatoes, minced garlic, chicken broth, and some freshly cracked pepper to the slow cooker. Stir briefly to distribute the garlic and pepper.
Place a lid on the slow cooker and cook on high for three hours, or until the potatoes are fork tender. You can test the tenderness by lifting the lid just long enough to pierce the potatoes with a fork.
Take the lid off the slow cooker and add the cream cheese, milk, and butter. Stir to combine the ingredients and mash the potatoes. For an extra smooth mashed potato, use a hand mixer to briefly whip the potatoes until smooth.
Taste the potatoes and add salt or pepper if needed. Serve immediately, or switch the slow cooker to the "warm" setting until ready to serve.