Place potatoes into a large saucepan with water to cover. Bring to the boil and cook until tender. Meanwhile, saute leeks in butter until translucent.
When potatoes are done, skin them while they are still hot and cut them into bite sized pieces. Place potatoes into a stock pot with chicken stock and leeks. season with salt and pepper. Cook over medium heat until simmering, then remove from heat and stir in milk. Serve immediately.
Made this soup the other day, and came out amazing. I had this at a 5 star hotel and this soup came very close in taste. I used more potatoes to make a thick sauce, blended it with a soup blender for a smooth , i will me making this regularly! - 19 May 2012