Peel 4 lbs of russet potatoes and rinse them in cold water. If the potatoes are very large, cut them in half. For the smoothest texture, remove any small knots with a spoon or potato peeler tip.

Place the peeled potatoes in a large pot (5 Qt+) and cover them completely with cold water.

Bring the water to a boil, then partially cover the pot and continue to cook at a light boil for 20-25 minutes, or until the potatoes are tender and easily pierced with a knife. Be careful not to overcook.

Drain the cooked potatoes thoroughly and transfer them hot to the bowl of a stand mixer.

Mash the hot potatoes lightly by hand with the whisk attachment to break them up.

Fit the mixer with the whisk attachment and begin mixing on low speed for 30 seconds.

Increase the mixer speed to medium and slowly drizzle in 1 to 1 1/4 cups of hot milk until your desired creamy texture is achieved.

With the mixer still running, add the 16 Tbsp of softened unsalted butter, one tablespoon at a time, waiting a few seconds between each addition for it to incorporate. Continue mixing until the potatoes are whipped and fluffy.

Add 1 1/2 tsp salt, or season to taste, and mix briefly to combine.

Garnish with 1 Tbsp fresh parsley or chives, finely chopped, if desired, before serving.