Mashed Potatoes with Leeks and Sour Cream

I love mashed potatoes to begin with.  This version takes it to a whole new level!  It is absolutely delicious!  Creamy and delicious!  Enjoy!

Ingredients:
-1 (5 lbs) bag of yukon potatoes, peeled and quartered
-4 large leeks, washed, peeled and sliced
-2 Tbs unsalted butter, plus 1/2 cup
-2 cups chicken broth
-salt
-white pepper
-1 cup sour cream
-1/2 cup whole milk
Directions:
Cook potatoes in boiling water until nice and tender.
Meanwhile, melt 2 Tbs butter in large saute pan.  Add leeks and sweat until soft and translucent.  Add chicken broth, a little salt and white pepper.  Simmer for about 3 minutes.  Pour the mixture into blender and puree.  Set aside.
When potatoes are cooked, drain and mash them with a masher.  Add the leeks, sour cream, 1/2 cup butter and milk.  Mix well together.  Season to taste with salt and white pepper.  Enjoy!