(Serves 6)

For bechamel:
3 tablespoons unsalted butter
3 tablespoons all-purpose flour
1/4 cup minced onion or shallot
1 small dried red chile (preferably Japanese), whole
1 small bay leaf
Kosher salt
2 1/2 cups whole milk

For casserole:
1/2 pound calamarata or elbow macaroni
2 tablespoons olive oil from tuna
Two (6-ounce) cans imported tuna packed in olive oil
4 ounces Gruyere cheese, grated (1 cup tightly packed)
3 tablespoons minced fresh flat-leaf parsley
1 1/2 cups (2 ounces) fresh bread crumbs
1 1/2 ounces Parmesan cheese, freshly grated (1/3 cup tightly packed)