Pizzoccheri are the buckwheat tagliatelle of the Valtellina, boiled with cabbage and potato and bound with butter, garlic, sage and melted Valtellina Casera, and putting them in bread produces one of the frankest carbohydrate-on-carbohydrate sandwiches in the Italian repertoire. This is a heavy mountain plate, eaten in a cold valley, asked to become portable. The honest thing to say about it is that it makes no attempt to be light: short dark pasta, starchy potato and a quantity of melted cheese, packed into a roll, is a deliberate excess rather than an accident, and the panino works only if it leans into that instead of pretending otherwise.
The craft is heat and the moisture the dish carries. Drained loose, pizzoccheri are buttery and slack and would slide straight out and soak the crumb through, so for bread the dish is taken thick and slightly set, the cheese still warm enough to hold the pasta together but cool enough to bind rather than run. The roll is chosen sturdy and is often pressed or warmed so the heat firms the bread against the filling instead of letting it go to paste; an overfilled one fails at the first bite. There is no point adding a sauce, because the butter and the Casera are already the whole statement, and the sandwich is eaten warm, straight from that assembly, when the cheese is at its most binding and the contrast of crust against soft pasta is sharpest.
The Valtellina and the wider Alpine kitchen fold several of these heavy starch dishes into bread, and each is its own subject rather than a version of this one. There is the sciatt, the buckwheat-battered Casera fritter tucked into a roll, the polenta taragna with the same mountain cheeses pressed and griddled, and the lighter hand that cuts the cheese back toward a vegetable build. Each is a different Valtellina plate forced between two pieces of bread, and each deserves its own article rather than being crowded in here.