Melt the butter in a medium sized saucepan on high.
Add the onion and garlic, and saute for 2 minutes or until they soften.
Add the Jerusalem artichokes, and continue to sauté for 2 more minutes.
Pour in the chicken stock, and simmer the blend until the artichokes have softened.
Pour in the cream and bring the mixture to a boil. Sprinkle with salt and pepper.
Purée the soup in a blender until smooth. You can strain it through a sieve for an even smoother result.
Sprinkle chives over the soup, and serve it warm.