Pommes Dauphine (Potato and Choux Puffs)

Prepare the potatoes. Peel the potatoes, cut into roughly 3cm chunks and rinse under cold water until it runs clear. This washes away surface starch that would otherwise make the mash gluey. Set aside ready for boiling.

Boil until tender. Cover with cold water, stir in the 10g salt and bring to the boil, then simmer for 10-15 minutes until a knife slides in with no resistance. Salting the water now seasons the potato right through rather than only on the surface. Drain well in a colander.

Dry the potatoes. Tip the potatoes back into the pot over low heat and shake for about 1 minute to drive off excess moisture. Drier potato needs less butter and egg to hold together, which keeps the finished puffs light rather than heavy. Pass the hot potato through a ricer or food mill for a smooth purée.

Season the purée. Stir the melted butter and grated nutmeg into the riced potato, then cover to keep warm. Keeping it covered stops a skin forming on top while you make the choux.

Build the choux paste. Bring the milk, water, 50g butter and salt to a full boil in a saucepan. Take off the heat, tip in the flour all at once and beat hard with a wooden spoon until it forms a smooth paste.

Dry the paste. Return the pan to low heat and stir for 1-2 minutes until the paste pulls away from the sides into a ball and a thin film forms on the base of the pan. Drying it off this way lets the paste absorb more egg later, which is what gives the puffs their rise. Tip into a bowl and cool for 3 minutes.

Beat in the eggs. Add the beaten eggs a little at a time, beating well after each addition, until the mixture is glossy and falls from the spoon in a thick V-shape. Working the eggs into warm, not hot, paste lets them emulsify fully without scrambling.

Combine and season. Fold the choux paste into the potato purée in a rough ratio of two parts potato to one part choux, until streak-free. Season with the black pepper.

Fry the puffs. Heat the oil in a large heavy pot to 170°C. Using two teaspoons, drop 15ml portions close to the oil's surface, frying 8-10 at a time for 3-4 minutes, turning as they puff and turn golden all over. The puffs roll over by themselves as trapped steam pushes outward; any hotter and they would brown before fully expanding.

Drain and serve. Lift out with a spider strainer and drain on kitchen paper, keeping finished batches warm in a 100°C oven while you fry the rest. Scatter with a little salt and serve immediately while the crust is still crackling. Never leave hot oil unattended while frying in batches.