Vichyssoise
["4 leeks", "1 Tbsp. butter", "5 large red potatoes or 4 Idaho bakers", "1 Tbsp. salt", "1 c. thick cream *", "4 Tbsp. minced chives", "1 medium onion", "3 c. water", "1 c. milk, half and half", "freshly ground black pepper"]
["*Mix 1/3 cup sour cream with 2/3 cup unpasteurized heavy cream, shake well and let stand at room temperature for 8 hours."]
["leeks", "butter", "red potatoes", "salt", "thick cream", "chives", "onion", "water", "milk", "freshly ground black pepper"]