In heavy saucepan over medium heat, sauté leek, potato and parsley in the butter until the potato is tender and leek is golden, about 12 minutes. Sprinkle flour over potato mixture and add salt and pepper to taste. Stir continuously for 2 more minutes. Add clams and clam juice; slowly stir in cream. Cook while stirring (but do not allow to boil) for 5 minutes or until thick and hot. Garnish with chives and serve hot. Serve in hollowed out small rounds of crusty bread for a complete meal.