Slowcooker Potato and Leek Soup

Ingredients:1 kilo of peeled and sliced.diced potatoes
2 large leeks - cut, cleaned and diced
20g butter
750ml (3 cups) chicken stock (vegetable stock if you wish)
1/2 tsp black pepper
1 tin evaporated milk or 2/3 cup cream

Method:
In a saucepan, melt your butter and add leeks, sweat off - ensure they become soft and translucent.
Put your potatoes in your slow cooker then add leek, stock and pepper
Set onto high for 3 hours or low for 5-6 hours.
20 minutes before serving, and transfer the mix to food processor, whizz until smooth.  If you have a bamix stick blender you could use this too directly in the pot (turn off the power first to the slowcooker).
At this point add your cream/evaporated milk and then return to the stock pot to do a final heat up for 20 minutes.