Classic Macaroni and Cheese (America's Test Kitchen)

Step 1

For the bread crumbs:

Step 2

Pulse bread and butter in food processor until crumbs are no larger than 1/8 inch, ten to fifteen 1-second pulses and set aside.

Step 3

For the pasta and cheese:

Step 4

Adjust oven rack to lower-middle position and heat broiler.

Step 5

Bring 4 quarts water to boil in Dutch oven over high heat.

Step 6

Add macaroni and 1 tablespoon salt; cook until pasta is tender; drain and set aside in colander.

Step 7

In now empty Dutch oven, heat butter over medium-high heat until foaming.

Step 8

Add flour, mustard, and cayenne and whisk well to combine.

Step 9

Continue whisking until mixture becomes fragrant and deepens in color, about 1 minute.

Step 10

Gradually whisk in milk; bring mixture to boil, whisking constantly (mixture must reach full boil to fully thicken).

Step 11

Reduce heat to medium and simmer, whisking occasionally, until thickened to consistency of heavy cream, about 5 minutes.

Step 12

Off heat, whisk in cheeses and 1 teaspoon salt until cheeses are fully melted.

Step 13

Add pasta and cook over medium-low heat, stirring constantly, until mixture is steaming and heated through, about 6 minutes.

Step 14

Transfer mixture to broiler safe 9 by 13" baking dish and sprinkle evenly with bread crumb mixture.

Step 15

Broil until crumbs are deep golden brown, 3 to 5 minutes, rotating pan if necessary for even browning.

Step 16

Cool about 5 minutes, then serve.