Prepare the potatoes by peeling them if desired (you can also leave the peels on), removing any bruised areas, and cutting them into 2-inch pieces. Place them in a large pot, cover with water, add up to 1/2 teaspoon of salt, and bring to a boil. Let them boil for 15 to 17 minutes until fork-tender.
In the meantime, combine the milk and butter in a small saucepan over low heat. Cook until the butter is melted, then remove from heat, being careful not to let the mixture boil.
When the potatoes are cooked, drain and return them to the pot. Pour in the milk and butter mixture, and mash the potatoes with a handheld masher or a handheld electric mixer (for a creamier texture) until smooth. Taste, and add salt, pepper, more butter, and fresh herbs as desired. For additional flavor, consider adding up to 1/2 cup sour cream. Enjoy warm!
Serve on the side of meat or fish or as the base for a gravy or stew.
Leftovers will last in an airtight container in the fridge for 2 to 3 days. Reheat in the microwave for 1 to 2 minutes. You may need to add a splash or milk or some melted butter and stir before microwaving to prevent drying out the potatoes.
Purple potatoes are earthier than other varieties, so you may need to add more butter, salt, pepper, or herbs to reach your desired flavor. The nutrition facts listed here do not take into consideration added salt or other fix-ins.