Gattò di Patate Napoletano

Ingredients

• 1.2 kg floury potatoes, boiled whole, unpeeled
• 60 g unsalted butter, plus extra for the dish
• 80 g Parmigiano-Reggiano, finely grated
• 2 eggs, whole, beaten
• 1 pinch nutmeg, freshly grated
• 100 g salame napoletano, sliced
• 200 g fior di latte mozzarella, squeezed dry on paper towel, cut into small cubes, brought to room temperature
• 60 g fine dried breadcrumbs, for lining and topping
• 1 tsp fine sea salt

Method

1. 1
   Place the potatoes, unpeeled, in a large pot of cold salted water. Bring to the boil and cook until a skewer passes through the centre without resistance. Drain immediately and peel while still hot — handling them with a cloth if necessary. Pass at once through a potato ricer into a wide bowl. Do not press or work the purée beyond what the ricer demands. The result must be dry, light, and free of lumps.
2. 2
   While the riced potato is still hot, add the butter in pieces and work it in with a wooden spoon until fully absorbed. Add the grated Parmigiano, the beaten eggs, and the pinch of nutmeg. Mix to a smooth, uniform mass. Season with salt. The mixture must hold its shape when mounded — if it slackens or appears wet, the finished cake will not set.
3. 3
   Preheat the oven to 190 °C. Butter a round baking dish or cake tin of approximately 24 cm diameter generously on all sides and the base. Coat the interior entirely with breadcrumbs, tapping out any excess. The breadcrumb lining must be even and unbroken — it is the structural crust that holds the cake when sliced.
4. 4
   Spread half the potato mixture into the dish in an even layer, pressing it gently to the sides and base. Lay the sliced salame napoletano over the potato in a single layer, then distribute the cubed mozzarella evenly across the filling. Spread the remaining potato mixture over the filling, smoothing the surface level with the rim of the dish. The potato layers on each side must be substantial — a thin layer will crack and cannot support the filling.
5. 5
   This is where the dish lives or dies. Scatter a generous, even layer of breadcrumbs over the top surface and dot with small pieces of butter. Slide into the preheated oven and bake for 30 to 35 minutes. The top must turn a deep, even golden brown — not pale, not merely coloured. A pale crust lacks both flavour and the structural rigidity to survive slicing; the cake will collapse. When the crust is deep gold and the edges show the same colour pulling away from the dish, the gattò is done.
6. 6
   Remove from the oven and allow to rest in the dish for 10 minutes before cutting. This rest allows the interior to firm. Run a knife around the edge, then cut into wedges in the dish and lift each portion with a palette knife. The slice must hold its form, showing the filling as a distinct band at the centre.