Wash the leeks and slice off the top green parts, you can keep the green parts for something else, take off the tough outer layer, and discard. Finely chop the leeks the best way to do this is to cut them lengthwise into three sections then gather round the segments and chop them.

Put the leeks into a colander and rinse them thoroughly this is particularly crucial if you are using organic or home grown leeks soil or sandy bits often get in the outer layers of.

Finely chop the onion and crush the garlic I now use a small micro plane grater for garlic it seems to do the job much better than a crusher. Peel and chop the potatoes into small cubes, melt the butter in a saucepan over a medium heat.

Turn the heat to low then add the leeks, onions, garlic and potatoes to the pan cook on a low heat for 10 minutes turning the ingredients 2 or 3 times while cooking

Add the stock and milk to the pan and cook for a further 20 minutes until the potatoes are softened and cooked through.

The soup is now ready to serve as a good warming main meal, the texture thick and with the vegetables a little chunky. If you wish a less rustic soup the cool it for about 5 minutes and then force through a large sieve or better still push it through a mouli.

You can use a food processor but be careful not to over process as potato tends to go like glue in a blender/processor.