Step 1

Peel the potatoes and slice them into 1 to 2-inch chunks.

Step 2

Add the potatoes to a large pot and cover them with cold water. Bring the water to a boil then reduce the heat to a simmer. cook for 15 to 20 minutes or until the potatoes are very tender.

Step 3

Drain the potatoes and return them to the pot then place the pot back on the stove over medium heat. Cook for 1 or 2 minutes while stirring until all the extra water evaporates.

Step 4

Use a potato masher to mash the potatoes then add 1/2 cup milk, all of the butter and all of the sour cream. Stir well then add more milk until you get your desired consistency.

Step 5

Spread the mashed potatoes into a 13x9 inch baking dish, cover with plastic wrap and store in the refrigerator for up to 2 days.

Step 6

Preheat the oven to 350°F, remove the plastic wrap and pour the melted butter on top of the potatoes. Bake for 40 to 45 minutes until hot all the way through. If the potatoes start to brown on top you can place some aluminum foil over the top to prevent them from browning too much.

Step 7

Garnish with chopped parsley or chives.

Step 8

Remove the plastic wrap and pour the melted butter on top of the potatoes. Heat in the microwave on high power for 12 to 15 minutes, stopping to stir every 5 minutes.