Step 1

Combine the potatoes, 4 cups of broth, 1 stick (1/2 cup) of the butter, garlic, and 1/2 teaspoon salt in the basin of a slow cooker. Add additional broth if needed to cover the potatoes. Cook on high for 4-6 hours or until the potatoes are very tender. Stir occasionally throughout the cooking time to make sure the potatoes cook evenly.

Step 2

Drain off and reserve the majority of the cooking broth (it doesn't have to be completely dry, but you want to get most of it).

Step 3

Mash the potatoes using a hand-held potato masher until no lumps remain. Then, mash in additional salt to taste, as well as the remaining butter, sour cream, and whole milk, starting with 1/4 cup and adding more until the potatoes reach your desired consistency. You can also add in more of the cooking broth to thin it out.

Step 4

Sprinkle on chopped chives, cover the potatoes, put the slow cooker to warm, and then serve.