Bring a large pot of generously salted water to a boil. Drop the potatoes in and cook until a fork can easily penetrate into a potato, about 30 minutes.
Oil a 9x13 inch pan with extra virgin olive oil. Set aside
Pre-heat the oven to 375 degrees
Drain the potatoes and transfer them to a large mixing bowl. While the potatoes are still warm out the potatoes through a ricer and mix well with a spatula until smooth.
Add the milk, butter and cheese to the potatoes. Taste for seasoning and add salt as desired. Add the eggs to the mixture and mix until well combined.
Sprinkle bread crumbs over the bottom and sides of the pan.
Spread half of the potato mix evenly into the pan.
Over the potatoes put a layer of provolone followed by a layer of ham and then mozzarella.
Spread the rest of the potato mix into the pan. With a fork refine the surface and create some grooves.
Drizzle some extra virgin olive oil and a thin coat of breadcrumbs.
Bake the Gateau for 45-60 minutes. At the end, place the Gateau under the broiler to give it a little color.