This recipe requires just four ingredients and 10 minutes cooking time. Need we say more. If you're making a big batch, why not try freezing it to use later.
50g unsalted butter
50g plain flour
1.2 litres of stock or milk or a mix of the two
2 large leeks
Remove the outer leaves of the leeks, trim the tops and bottoms then slice them in half lengthways and wash under a cold tap to remove any dirt. Slice the leeks into 1cm-thick pieces then fry them with the butter in a pan over a medium heat until soft but not coloured.
Take off the heat and stir in the flour until combined with the butter, then add a little milk and stir well to avoid any lumps. Return to the heat and add the rest of the milk or stock (whichever you are using) gradually, stirring continuously until the soup boils and thickens. Season to taste.
To add a little something special it is nice to grate some cheddar over the soup when serving or, for a meaty version of the dish, you can even add some chopped bacon to the leeks are you are frying them.