A very simple and extremely tasty tart that I often make when leeks are in season. You can make your own pastry if you wish - I do when I have lots of time, but this works equally well with good quality ready-made flaky pastry, thus cutting down on time. Try to use small, thin leeks and try to get hold of little pink shallots - it just makes it so colourful when cut and served. This tart freezes beautifully; you just need about 3-4 hours to defrost it and then to reheat it, just pop it into the oven on a low heat for about 10 to 15 minutes. However, it is delicious served and eaten cold as well. Great picnic food or wonderful for a light & elegant luncheon dish. I also serve this at celebrations as part of a finger buffet - it can be baked in a square tin for events like that - making it easier to cut and portion. One point, this is what I would call a soft set tart - so when you take it out of the oven, do not be alarmed if it appears to be too soft; it will set as it cools, making it deliciously creamy and not at all rubbery! N.B. I have called this a bit of a French Tart, just a play on my Zaar name! But, it could be Welsh, using Welsh goat's cheese & Welsh leeks, or even English, you can obtain a wonderful array of English goat's cheeses now.