Mornay mac and cheese

Melt the butter in a medium high-walled saute pan, add the flour and whisk to a paste.

Cook the roux one to three minutes, just until the raw flour smell dissipates.

Stir in the milk a splash at a time, letting each splash fully incorporate into the clumps before the next; add more at a time once it is a thick bechamel.

Bring the bechamel to a very gentle simmer and cook about three minutes.

Kill the heat, stir in the cheeses and let the residual heat melt them into a smooth mornay.