Prepare the potatoes: Peel the potatoes and cut them into even 4 cm chunks. Rinse them under cold water until the water runs clear—this removes excess starch that can make the mash gluey. You'll feel the pieces become less slippery in your hands.

Boil the potatoes: Place the chunks in a large pot and cover with cold water by about 5 cm. Add a generous tablespoon of salt. Bring to a boil over high heat, then reduce to a steady simmer. Cook for 15–20 minutes, until a knife slides into the centre with absolutely no resistance. The potatoes should look slightly cracked at the edges, and the water will smell starchy and earthy.

Drain and steam dry: Drain the potatoes in a colander and let them sit for 2–3 minutes. Return them to the dry pot over low heat for 30 seconds, shaking gently. You'll see steam rising and the surface of the potatoes will look matte, not wet. This step is non-negotiable for fluffy mash.

Mash the potatoes: Pass the potatoes through a ricer or food mill into a large, warm bowl. If you don't have one, use a potato masher, but work gently—over-mashing activates the starch and turns the texture gluey. The potatoes should look like fluffy snow, pale and light.

Warm the butter and milk: In a small saucepan, combine the cubed butter and milk. Heat over low heat until the butter is just melted and the mixture is warm to the touch—about 60°C. Do not let it boil, or the milk will separate. You'll see small bubbles forming around the edge, and the smell will be rich and creamy.

Incorporate the liquid: Pour about half the warm butter-milk mixture over the riced potatoes. Using a wooden spoon or silicone spatula, fold gently until absorbed. Add the remaining liquid, the salt, and the white pepper. Fold until the mash is smooth, glossy, and holds a soft peak when you lift the spoon. The colour should be a warm, even ivory.

Add the final richness (optional): If using crème fraîche, fold it in now. It adds a subtle tang that mimics the richness you find in high-end restaurants. The texture will become even more silken, almost velvety to the touch of the spoon.

Plate with flair: To serve impressively, transfer the mash to a piping bag fitted with a large star nozzle and pipe tall rosettes onto warm plates. Alternatively, use a large spoon to create a dramatic swoop across the plate, then finish with a pinch of flaky sea salt and a scatter of fresh chives. The contrast of the pale, creamy mash against the dark herbs is stunning.