Barefoot Contessa's Grown-Up Mac and Cheese

1. Preheat the oven to 400°. Place bacon in one layer on a sheet pan and bake for 15 to 20 minutes until crisp. Crumble until coarse and set aside. Reduce the oven to 375°. Adjust the baking racks to accommodate 2 sheet pans.

2. Meanwhile, drizzle oil into a large pot of boiling salted water. Add the pasta and cook according to package directions until al dente, usually 6 to 8 minutes. Drain well.

3. Heat the milk in a saucepan, but don’t boil it. Melt 6 tablespoons of butter in a large (4-quart) pot and whisk in the flour. Cook over low heat for 2 minutes, stirring constantly with a whisk. Whisk in the hot milk to form a thick and creamy white sauce and cook, stirring, for about 2 minutes more. Off the heat, add the Gruyère, cheddar, Roquefort, one tablespoon salt, pepper, and nutmeg.

4. Combine the sauce with the cooked pasta and bacon, and stir until thoroughly combined. Place 6 individual gratin dishes on 2 sheet pans and spoon the pasta into them. (You can also use one 3-quart baking dish.)

5. Cube the bread, place it in a food processor fitted with a steel blade, and process until you have coarse crumbs. Melt the remaining 2 tablespoons of butter and add to the crumbs with chopped basil. Pulse the machine just to combine. Sprinkle the bread crumbs over the pasta and bake until the sauce is bubbly and the bread crumbs are golden, about 35 to 40 minutes.