Use the Whole Leek

Split a leek from the first fork of green leaves down through the root. Fan the layers apart under running water. For sliced leeks, swish the pieces in a bowl of cold water and lift them out by hand so the grit stays behind.

White shank

Slice crosswise into thin half-moons. For a soup base, soften two cups of sliced leek in a tablespoon of butter with a pinch of salt over medium-low heat for 8–10 minutes. Stir often and stop when the slices are silky.

Pale green

Slice the tender green section across the grain. Sauté it with the white section or soften it separately before folding into eggs or layering into a potato gratin.

Dark leaves

Separate and wash each leaf. Add a handful to a pot of vegetable stock for the last 20–30 minutes of simmering, then strain. Trim off dry or damaged tips.

Whole halves

Leave a thin piece of root attached to hold the layers together. Brown two cleaned halves cut-side down in a little oil, add enough stock to come a quarter of the way up, cover and simmer 12–20 minutes until a knife slides through the thick end.