Potato Leek Soup with Dill

1 Tbsp Butter3 Large Leeks (Thinly sliced and washed (white and light green parts only))2 Large Russet Potatoes (Peeled and cubed)3/4 Cup White Wine4 Cups Chicken Broth1 Cup Heavy Cream2 Tbsp Chopped Fresh Dill3/4 tsp Salt1/2 tsp PepperDill Sprigs for Garnish To wash the leeks...