Gattò di patate (from the French 'gâteau,' a linguistic relic of Bourbon-era French influence on Neapolitan court cuisine) is a sumptuous potato cake that represents the intersection of French technique and Neapolitan ingredient sensibility—a layered construction of mashed potatoes enriched with butter, eggs, salame, provola, and prosciutto, baked until golden-crusted outside and creamy-molten within. The preparation begins with floury potatoes boiled until completely tender, then riced or mashed while hot with generous amounts of butter, egg yolks, grated Parmigiano, salt, pepper, and a splash of milk. This enriched purée is spread in a buttered, breadcrumb-lined baking dish, then layered with cubes of provola affumicata (smoked provola), slices of salame or mortadella, cubed prosciutto cotto, and sometimes hard-boiled eggs. A second layer of potato purée covers the filling, and the top is scattered with breadcrumbs, dots of butter, and grated cheese. Baking at 180°C for 30-40 minutes produces a golden, crispy crust that shatters to reveal the molten interior—the provola stretches in long strings, the salame has rendered its fat into the surrounding potato, and the whole construction has fused into something far greater than the sum of its parts. Gattò is quintessential Neapolitan comfort food—served as a side dish, a light main course, or, in portable squares, as food for picnics and gita fuori porta (day trips). Like most great Campanian preparations, it's better the second day when reheated in a pan to re-crisp the exterior. The dish's French name and Neapolitan soul perfectly encapsulate the city's culinary history: aristocratic in origin, democratized by the people.
Rice or mash potatoes while hot. Enrich generously with butter, eggs, Parmigiano. Layer with provola, salame, prosciutto. Breadcrumb-crusted top and bottom. Bake until golden and crusty. Rest briefly before cutting.
The potato purée should be almost too rich—the baking firms it up. Smoked provola is essential for the authentic flavour. Some families add a layer of béchamel for extra creaminess. Leftover gattò, cut into squares and pan-fried until crispy on both sides, is magnificent.
Under-enriching the potato base (too plain). Using waxy potatoes (don't mash properly). Skimping on the filling. Not lining the pan with breadcrumbs (sticks). Cutting too soon (collapses). Under-baking (no crust forms).
La Cucina Napoletana — Jeanne Carola Francesconi; Arthur Schwartz, Naples at Table