Packed with iron, fibre and vitamin C, they offer many of the health benefits associated with garlic.

When shopping, avoid very fat leeks which tend to be woody and look for small or medium-sized ones which are sweeter and more tender.

Although the dark leaves are generally discarded, vibrant green tops usually indicate a healthy, fresh vegetable.

Leeks need to be washed thoroughly to loosen all the soil trapped between their leaves. And a final word of warning . . . always buy more than you think you'll need as you'll be discarding a surprising amount of leaves before cooking them!

Gary Rhodes' leek, ham and Brie slice Serves 4 Large knob of butter Three leeks, sliced Salt and pepper 375 g ready-rolled puff pastry 175g piece of ham, cut into cubes 300-350g Brie, cut into thin wedges One egg yolk A splash of milk Olive oil, for drizzling Melt the butter in a large saucepan and, once sizzling, add the leeks and cook over a medium heat, without colouring, until they start to soften. Season with salt and pepper, then drain and leave to cool.

Preheat the oven to 2000C/gas mark 6. Lightly brush a baking tray with oil, unroll the puff pastry and place on top. Using a fork, prick the base several times, leaving a clear two cm border around the outside.

Add the ham to the leeks and spoon onto the pastry.

Arrange the Brie wedges across the surface. Brush the pastry border with the egg yolk mixed with the milk.

Bake in the oven for 20-25 minutes until the pastry is golden brown. Leave to cool slightly before drizzling with a little olive oil. Cut into slices to serve.