Saffron, leek and scallop soup

This is basically a leek and potato soup, spiced with saffron and used as a foil for the sweetness of the seared scallop. The secret is to be sparing with most of the ingredients: small amounts of potato will thicken quite a lot of liquid and too much saffron will over-power everything else involved. Try not to look for a deep-yellow colour, for instance, as some sign of success - a custard-coloured soup will be too strong.