Vichyssoise

Ingredients

• 6 tablespoons butter
• 4 leeks, white part only, cleaned well and sliced in thin rounds
• 1 onion, quartered and sliced thinly
• 8 medium potatoes, peeled and quartered
• 8 cups strong pareve stock
• 1-1/2 cups milk
• 1-1/2 cups coffee cream
• 4 cups whipping cream, divided
• 1/2 cup chopped chives, divided