Potato Leek Soup
["3 Tbsp. unsalted butter", "2 large leeks", "3 c. rich chicken broth", "2 large baking potatoes", "1 1/2 c. watercress", "heavy cream"]
["Melt butter.", "Add thinly sliced leeks and saute until soft (8 minutes).", "Stir in chicken broth and potatoes, peeled and sliced au gratin style.", "Partially cover; simmer for about 10 minutes. Using a wooden spoon, mash some potatoes against the side of the pan.", "Stir in coarsely chopped watercress.", "Simmer for 1 minute. Serve in bowl.", "Season with salt, pepper and swirl 1 tablespoon heavy cream."]
["unsalted butter", "leeks", "chicken broth", "baking potatoes", "watercress", "heavy cream"]