This is not a sandwich you assemble. It is a sandwich you compose. Each ingredient must earn its place, and there are only four of them. Bresaola, the air-dried beef of the Valtellina valley in Lombardy. Arugula, peppery and wild. Parmigiano-Reggiano, aged until it crumbles. Olive oil, the best you own.

Americans layer sandwiches with five meats, three cheeses, and condiments that mask everything beneath them. Italians understand that restraint creates intensity. When you eat this panino, you taste the bresaola. You taste the arugula against it. The Parmigiano adds salt and depth. The oil binds everything without intruding.

Do not heat this sandwich. Do not press it. The bresaola is a cured meat of great delicacy, and heat would turn it to leather. You are not making a panini. You are making a panino, which is simply the Italian word for a sandwich, and this one is served at room temperature, as the Lombards have eaten it for generations.