Leek and Potato Soup

An oldie, but a goody. This soup ticks almost every soup box going; it's soothing, nourishing, frugal and delicious. It's beauty lies within it's simplicity, highly, highly recommended cooking and eating.
Ingredients:
3 large potatoes, peeled and sliced
4 leeks, thinly sliced
1 onion, finely chopped
50ml chicken
Salt and pepper.

To cook:
Sweat the leeks in olive oil or butter over a low heat for 5 mins. Add the onion and continue cooking until very soft, slow cooking is best for this.
Add the chicken stock and potato, bring to the boil and reduce down to a simmer for about 20 mins.
Check that the potatoes are thoroughly cooked, then, whizz everything together away from the heat. Season to taste and serve with good bread and butter.