Step 1: Prepare and Bake the Potatoes
Preheat your oven to 400°F (200°C). Scrub the potatoes thoroughly under running water and pat them completely dry. Using a fork or a sharp knife, pierce each potato several times all over. This allows steam to escape during baking and prevents the potatoes from exploding in the oven. Place the pierced potatoes directly on the oven rack or on a baking sheet. Bake for 60 to 75 minutes, or until the skins are papery and crisp and the potatoes are completely tender when pierced with a skewer or fork. The skewer should slide in and out with absolutely no resistance.

Step 2: Warm the Dairy and Butter
About 10 minutes before the potatoes are done baking, warm your dairy and butter. You can do this in a small saucepan over low heat or in a microwave-safe bowl. Gently heat the cream (or milk) and the butter together until the butter is fully melted and the liquid is hot to the touch but not boiling. Keeping the dairy and fat warm is a crucial step; adding cold liquids to hot potatoes can result in a gluey texture and prevent them from absorbing the fat properly.

Step 3: Scoop the Potato Flesh
Once the potatoes are fully cooked, carefully remove them from the oven. They will be extremely hot. Using an oven mitt to hold a potato, slice it in half lengthwise. Use a large spoon to scoop the hot, fluffy interior out of the skins and into a large bowl. Discard the skins (or save them to make crispy potato skins later!). Work quickly to ensure the potatoes stay as hot as possible.

Step 4: Mash the Potatoes
Immediately after scooping, it’s time to mash. While the potato flesh is still steaming hot, mash it thoroughly. For the fluffiest possible texture, press the cooked potato through a potato ricer or a food mill. This breaks down the potato into fine, rice-like strands without overworking the starch. If you don’t have a ricer, a hand-held potato masher will also work well. Mash until there are no large lumps remaining. Avoid using a food processor or an electric hand mixer, as the high speed of the blades will almost certainly overwork the starches and turn your potatoes into a gummy paste.

Step 5: Add the Hot Liquid and Season
Pour about half of the hot cream and butter mixture over the mashed potatoes. Gently fold it in with a spatula or wooden spoon until just combined. Add the remaining liquid in splashes, mixing gently after each addition, until the potatoes reach your desired consistency. You may not need all the liquid, so add it gradually. Finally, fold in the salt and freshly ground black pepper.

Step 6: Taste and Serve
Give the mashed potatoes a final taste and adjust the seasoning with more salt and pepper if needed. Transfer them to a warm serving bowl, top with an extra pat of butter, and garnish with fresh chives or parsley. Serve immediately.