Macaroni and Cheese

For topping (it made way too much topping- I'll half it next time)
1/2 stick unsalted butter
2 cups panko (coarse Japanese bread crumbs) or 3 cups coarse fresh bread crumbs (from 6 slices firm white sandwich bread)
1/4 pound coarsely grated extra-sharp Cheddar (1 1/2 cups)
1/2 cup grated Parmigiano-Reggiano

For macaroni and sauce (made enough to fill 9x13 pan all the way to the top)
1 stick unsalted butter
6 tablespoons all-purpose flour
5 cups whole milk
1 pound coarsely grated extra-sharp Cheddar (6 cups)
1/2 cup grated Parmigiano-Reggiano
1 pound elbow macaroni

Preparation

Make topping:
Preheat oven to 400°F with rack in middle.

Melt butter, then stir together with panko and topping cheeses in a bowl until combined well.

Make sauce:
Melt butter in a heavy medium saucepan over medium-low heat and stir in flour. Cook roux, stirring, 3 minutes, then whisk in milk. Bring sauce to a boil, whisking constantly, then simmer, whisking occasionally, 3 minutes. Stir in cheeses, 2 teaspoons salt, and 1/2 teaspoon pepper until smooth. Remove from heat and cover surface of sauce with wax paper.

Make Macaroni:
Cook macaroni in a pasta pot of boiling salted water (2 tablespoons salt for 4 quarts water) until al dente. Reserve 1 cup cooking water and drain macaroni in a colander. [I skipped adding the water.] Stir together macaroni, reserved cooking water, and sauce in a large bowl. Transfer to casserole dish.

Sprinkle topping evenly over macaroni and bake until golden and bubbling, 20 to 25 minutes.

Cooks' notes:
• Topping can be made 1 day ahead and chilled, covered.

adapted from epicurious.com
Full post to come