In a large 5 or 6 quart slow cooker add diced potatoes, minced garlic and broth. Cook on high for 3-4 hours until potatoes are very fork tender.
Once potatoes are done cooking, place slow cooker on warm setting and add in butter, sour cream and 1/2 cup of milk to start. Use a potato masher to mash potatoes until they reach your desired consistency. I happen to like my potatoes super creamy, so I mash them until they’re completely smooth.
Transfer to a large warm casserole dish for serving, add a pat of butter, a sprinkle of fresh thyme, and a little freshly ground black pepper. Serves 10.
If you want a richer, very silky smooth version, you can use a ½ cup of butter and whole milk.
If you don't like potato skins, feel free to peel your potatoes before dicing and placing in the slow cooker. They're delicious!
If you're keeping the potatoes warm in your slow cooker you may need to add more milk before serving to keep their silky smooth texture. Mashed potatoes can be kept warm in the slow cooker for up to 3 hours.