2 Tbsp butter
2 teaspoon chopped garlic
1/3 cup chopped onion
1 pound Jerusalem artichokes (washed, sliced 1/4-inch thick)
2 cups chicken stock
1 cup cream
salt and pepper
1 teaspoon chopped chive

Melt the butter in a medium-size saucepan over high heat, add the garlic and onion and cook until soft, about 2 minutes (if you have time to let the onions caramelize a bit, do so).   Add the Jerusalem artichokes and sauté about 2 minutes. Add the stock and simmer until the chokes are tender. Add the cream and bring back to a boil. Season with salt and pepper. Purée in a blender until smooth. Strain through fine sieve. Keep warm. Sprinkle with the chive. Serve.

– http://www.epicurious.com