Ingredients

Equipment Needed

• •10-inch round baking dish or springform pan
• •Potato ricer or food mill
• •Large pot for boiling potatoes

Instructions

1. 1

   Cook the potatoes

   Place whole, unpeeled potatoes in a large pot. Cover with cold water by two inches and add a generous amount of salt. Bring to a boil, then reduce to a steady simmer. Cook until a knife slides through the center without resistance, 35 to 45 minutes depending on size. The potatoes must be cooked through completely. Underdone potatoes will not mash properly and your gatto will be lumpy.

2. 2

   Prepare the pan

   While the potatoes cook, butter a 10-inch round baking dish or springform pan generously. Coat the bottom and sides completely with breadcrumbs, tapping out any excess. The breadcrumbs create the golden crust that defines this dish. Set aside.

3. 3

   Rice the potatoes

   Drain the potatoes. While still hot, peel them using a kitchen towel to protect your hands. Pass them immediately through a ricer or food mill into a large bowl. Work quickly. Hot potatoes rice smoothly; cold potatoes become gluey.

   Never use a food processor or blender for mashed potatoes. The blade ruptures the starch cells and creates paste. A ricer or food mill is essential.
4. 4

   Enrich the potatoes

   Add the butter to the hot riced potatoes and stir until melted and absorbed. Add the warm milk gradually, stirring constantly, until the mixture is smooth and creamy but still holds its shape. You may not need all the milk. The potatoes should be rich but not loose.

5. 5

   Add the binding

   Let the potato mixture cool for 10 minutes. It must not be hot or the eggs will scramble. Beat in the egg yolks one at a time, stirring vigorously after each addition. Add the Parmigiano-Reggiano and nutmeg. Season generously with salt and pepper. Taste it. The mixture should be well-seasoned on its own.

6. 6

   Prepare the filling

   In a bowl, combine the cubed provola, mortadella, salame, and fresh mozzarella. Toss gently to distribute. This is the treasure hidden inside your potato cake.

   Provola affumicata, smoked provola, adds another layer of flavor. If unavailable, scamorza works well. What you must avoid is the rubbery processed mozzarella sold in American supermarkets.
7. 7

   Assemble the gatto

   Preheat your oven to 375°F. Spread half of the potato mixture into the prepared pan, pressing it evenly across the bottom and slightly up the sides. The layer should be about one inch thick. Scatter the filling mixture evenly over the potatoes. Top with the remaining potato mixture, spreading it gently to cover the filling completely. Smooth the top with a spatula.

8. 8

   Finish and bake

   Scatter the remaining breadcrumbs over the top. Dot with small pieces of butter. Bake in the center of the oven until the top is deeply golden and the edges are pulling away from the pan, 45 to 50 minutes. The internal temperature should register at least 165°F if you are uncertain.

9. 9

   Rest and serve

   Remove from the oven and let rest for at least 15 minutes before slicing. This is not optional. The gatto needs time to set. If using a springform pan, release the sides after resting. Slice into wedges like a cake. The cheese inside will pull in long strings when you serve it warm. This is precisely correct.

   Gatto is excellent at room temperature and even better the next day, reheated in a moderate oven until warmed through. Neapolitan families often make it specifically to eat cold for lunch.

Chef Tips

• •Use starchy potatoes, not waxy ones. Yukon Gold or russet work well. Waxy potatoes like Red Bliss will not rice properly and the texture will be wrong.
• •The egg yolks are your binding agent and must be added when the potatoes have cooled somewhat. Too hot and they scramble. Too cold and they will not incorporate smoothly. Lukewarm is correct.
• •Provola is the traditional cheese, but it can be difficult to find. Scamorza is the closest substitute. In desperation, low-moisture mozzarella will work, though the flavor suffers. Fresh mozzarella alone is too wet.
• •Neapolitans sometimes add a layer of hard-boiled eggs, sliced thin, between the potato and filling. This is traditional for Easter. You may include them if you wish.

Advance Preparation

• •The potato mixture can be prepared through the egg yolk step up to one day ahead. Refrigerate covered. Bring to room temperature before assembling.
• •The fully assembled, unbaked gatto can be refrigerated overnight. Add 10 minutes to the baking time if baking cold.
• •Leftover gatto keeps three days refrigerated. Reheat in a 325°F oven until warmed through, about 20 minutes. Some prefer it at room temperature.

Frequently Asked Questions

Nutrition Information

1 serving (about 290g)