Leek Gratin

I like to demonstrate this gratin at cooking classes. As I pour the cream over the dish, my students have that horrified I’ll-never-make-that look, but when I serve the leeks, usually at the same time as other things, I hear, “Ah, the leeks ...”

In classic French cooking, tradition dictates that you blanch the leeks and then cover them with a Mornay or béchamel sauce (see Cauliflower Gratin) and bake or broil them until a crust forms on top. T