Rinse and peel the potatoes. I leave small potatoes whole, but chop any larger potatoes to be the same size as your smallest ones. 

Place the potatoes in the bottom of a large pot. Fill with cold water, add 3 teaspoons salt, and then place the pot on the stove over high heat. Cover and bring to a boil. Boil for 18-22 minutes, or until a fork easily pierces the potato. 

Drain the potatoes then return the pot to low heat. Add the potatoes back to the pan and cook, stirring, for about 1 minute to allow the potatoes dry. Roughly mash the potatoes using a potato masher or two forks, then transfer them to the bowl of an electric mixer or keep the potatoes in the pot and use handheld beaters. 

Heat the milk in another sauce pan or in the microwave until hot, but not boiling. 

Use the whisk attachment to blend the potatoes on medium speed. Scrape the bowl, then add the butter, a few Tablespoons at a time, blending until melted. Add the hot milk and continue to beat on low speed until absorbed. Turn the speed up to medium high and blend until smooth. Season to taste with additional salt. Serve with a pat of butter on top and fresh parsley, if desired.