Leek And Potato Soup Base - cooking recipe

Ingredients

2 large leeks
2 tablespoons butter
1 medium onion, coarsely chopped
3 medium peeled potatoes, cut in chunks (Yukon Gold,Russet or Red)
2 cups vegetable stock or 2 cups chicken stock

Preparation

Cut off the coarse, green leaves on each leek up to the lightest green part;cut off the root.
To clean leeks,cut them length-wise without cutting through the root end.
Separate and fan out the leaves;place under running cold water to remove any grit.
Shake off any water.
Thinly slice crosswise.
In a large saucepan, melt butter on medium heat and stir in leeks and onion.
Cover and cook 10 minutes to *sweat* the vegetables without browning them,turning often.
Add potatoes and stock;cover pot to simmer 30 minutes until potatoes are tender, stirring often so that they do not stick to the bottom of the pot.
Puree soup with an immersion blender or food processor.
Divide mixture into containers, seal and freeze.