-
1
Preheat oven to 350u00b0 F. Lightly grease or spray a 9- by 13-inch (3-quart) baking dish. (If you care to warm your milk before adding it, which can help it incorporate into the sauce later, now's the time to place it in a large glass bowl and put it on a burner while the oven heats up.)
-
2
Fill a large pot with water and bring to a boil. Add the pasta and cook until very al dente (about 3 minutes shy of how you'd cook it normally for al dente doneness). Rinse under cold water to stop the cooking, drain, and set aside.
-
3
In a medium saucepan, melt the butter over medium heat. Add the chopped shallots (they'll be swimming in butter) and let them cook until translucent but not browned at all, about 5 minutes.
-
4
Add the chopped garlic and cook for 30 seconds, stirring constantly. Whisk in the flour and salt and cook, whisking constantly, for 1 minute.
-
5
Add the milk and continue to whisk constantly. Bring the mixture to a boil, then turn it down to low and continue to cook while you stir it until the mixture thickens, about 5 minutes. Add the herbs, wine, and mustard to the sauce, and continue to stir for 30 seconds. Then, add all the cheese except for 1/4 cup of the Parmesan. Stir until the cheese melts, then remove from the heat. Add the pasta to the cheese sauce.
-
6
Pour the mixture into your prepared pan. Top with the remaining 1/4 cup Parmesan cheese and the breadcrumbs.
-
7
Bake for 20 to 30 minutes, or until golden and bubbling on top. Depending on the size of your pasta, it will take more or less time.
-
8
Remove from the oven and transfer to a cooling rack. Cut into squares, garnish with flaky sea salt and extra herbs if you'd like, and then serve while still piping hot!
