Baked mac and cheese with Mornay sauce

Shred the cheeses on the large holes of a box grater and cube the mozzarella.

Cook the pasta.

Melt the butter and cook it over medium heat two to three minutes until it stops spattering, the stage just before browning, swirling regularly.

Whisk in the flour to a thick paste and cook two to three minutes until the raw flour smell dissipates, keeping the roux blonde.

Add the cold milk slowly and in stages, a cup first and then half a cup at a time, whisking each addition smooth before the next.

Whisk relatively constantly over medium heat until it comes to a bare simmer and is just thicker than heavy cream.

Put all the cheeses except the mozzarella in a heatproof bowl and pour the bechamel over them through a fine mesh strainer, folding and then whisking until the cheese is totally melted; this is a Mornay.

Season with kosher salt, pepper, optional cayenne and the whole grain mustard.

Combine the pasta and sauce in the casserole, stir in the cubed mozzarella, and top with the grated cheddar and Parmesan.

Bake at 375F for about 45 minutes, rotating once.

Rest 10 minutes before serving.

To freeze, cool about 30 minutes, divide into vessels, wrap tightly in aluminum foil and freeze two to four months.