Potato pizza recipe

Potato pizza
It is an irresistibly good savory preparation, because it is a concentrate of good things: creamy mashed potatoes, tasty salami, stringy cheese and, finally, a delicious external crust given by the breadcrumbs mixed with butter, pepper and grated cheese.
Ingredients
for a wheel of 28 cm in diameter and 6 cm in height.
2,5 Kg. Of potatoes, still to be peeled, possibly not new and with yellow flesh (but not essential as for crocchè)
4 large eggs
16 gr. salt
Pepper
About 60 grams of grated cheese (or as much as you like)
About 350 grams of mozzarella or scamorza (or how much you like)
About 100 grams of cured sausage cut into small pieces (or how much you like)
200 gr. of milk
80 gr. of butter
To cover you will need:
About 30 grams of butter in small pieces
Grated bread Grated
cheese
Salt and pepper
For the pan you will need:
Butter
Breadcrumbs
Method