Fill the 6 Quart Stock Pot with 3 ½ quarts of water. Place the pot over medium heat. Cover the pot with the lid. Bring the water to a rolling boil. Remove the lid. Season the water with a generous pinch of kosher salt.

Carefully add the peeled potatoes to the pot. Return the water to a medium boil. Cook the potatoes, uncovered, until fork tender, approximately 20-25 minutes.

Heat the milk (stock) in the1 Quart Saucepan over low heat. Add the rosemary sprigs to the liquid. Do not boil, simply steep the sprigs for 10 minutes to extract flavor. After ten minutes, remove the rosemary sprigs and discard.

Add the butter and allow it to melt. Add 1 teaspoon of kosher salt and ¼ teaspoon of freshly ground black pepper to the milk (stock). Stir the mixture to combine the ingredients and dissolve the salt.

Transfer the cooked potatoes to a baking sheet for 3-5 minutes. This will allow them to air-dry, removing some of the water.

While the potatoes are still warm, put them through a potato ricer or mash them with a manual potato masher.

In a large bowl, combine the potatoes with just enough milk or stock to bring mixture to your desired consistency. Season them with salt and pepper to taste.