A gattò is a savory potato pie layered with different meats and cheeses typical of the regions of Sicily and Campania. Nonna Liliana fills her gattò with savory prosciutto cotto and provolone, and makes it every Thanksgiving in place of mashed potatoes as a way of melding cultures.
Bring a large stockpot of generously salted water to a boil. Drop the potatoes in, whole, and cook until a fork can easily pierce a potato, about 30 minutes.
Preheat the oven to 375°F (190°C). Grease a 13 × 9-inch (33 × 23 cm) pan with olive oil. Set a