Baked mac and cheese with a 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, swirling, until it stops spattering and popping - the stage just before browning, when most of the moisture is driven off.

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

Add the cold milk slowly in stages, a cup and then half cups, whisking each until smooth.

Whisk fairly constantly over medium heat to a bare simmer, until it is just thicker than heavy cream; that is the bechamel.

Off the heat, pour the bechamel through a fine mesh strainer over all the cheeses except the mozzarella and fold, then whisk, until melted: a Mornay sauce.

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

Put the pasta in the casserole, then the sauce, and stir to disperse.

Stir in the cubed mozzarella, then top with the grated cheddar and Parmesan.

Bake at 375F about 45 minutes, rotating once, then rest 10 minutes before serving.

To freeze, cool about 30 minutes, portion, wrap tightly in foil and freeze up to two to four months.