Unbelievably Easy Crock Pot Garlic Mashed Potatoes

garlic, about 10 cloves, separated from the bulb and peeled

red potatoes, scrubbed clean and cut into 2-inch pieces

butter + more for serving as desired

salt + additional salt and freshly ground black pepper to taste

water or vegetable broth

half-and-half plus more as desired

Two-quart or larger Crock Pot