Vichyssoise  [caterers  course] 
Yield - 5 Quarts
Ingredients
6-8 Medium Idaho Potatoes
1 LB Margarine
4 Laarge Diced Leeks (White and Yellow Bases Only)
1 Bunch  Diced Shallots (White Bases Only)
1-1/2 Tbsp Chicken base
1 TSP White Pepper
1 CUP White Wine
1-1/2 Quarts Heavy whipping cream 
1 Quart Milk
1 Cup Shallot tops
Method
Peel potatoes and remove ALL brown and discolored areas. 
 Boil potatoes for 20 minutes or until the interiors are soft 
 when stuck with a knife. Do not over cook potatoes. 
 Drain potatoes, retain liquid, let the potatoes cool then mash with fork.
In a braiser and over low heat saute leek and shallot bottoms in the 
 margarine until clear, or about 10 minutes. 
 Add chicken base, white pepper, white wine, heavy cream, and milk; 
 simmer until soup starts to bubble. Add mashed potatoes and whisk vigorously, 
 if the soup is too thick add some of the potato water.
Chill the soup.
  
 Alternate Method
For a Creole touch boil the potatoes in just a hint of crab boil seasonings.
Plate Presentation
Just before serving, put the soup in a blender and whip on low speed for 20 seconds. 
 Garnish with shallot tops