(serves 6)
3 tbsp olive oil
1 lb sunchokes, unpeeled (about 4 medium/large sunchokes
2 waxy potatoes like Yukon Gold
1 celery rib (optional)
1 onion
5 cups stock
3 cloves garlic, minced
1 bay leaf
3/4c milk or cream
salt and pepper to taste
croutons or toasted pumpkin seeds, hazenut oil or pumpkin seed oil (optional toppings)

Chop sunchokes and potato into 1" cube or less size. Dice celery and onion. Heat olive oil in a soup pot, add chopped onion, celery, and garlic, and cook on medium-high heat until browned, about 10 minutes. Add stock and bay leaf and scrape the browned stuff off the bottom of the pot. Season with about 1⁄2 tsp salt and pepper to taste.

Bring to a boil, add chopped tubers, and then cover and cook on low for 20 minutes, or until potatoes are tender. Pour soup into a blender and puree until smooth (or use hand blender in pot), then return to pot and stir in milk or cream to desired consistency. Adjust seasonings.

Serve with roasted pumpkin seeds sprinkled on top or drizzled with one of the nut oils.
See also : http://homecooking.about.com/od/soups/r/blss36.htm Sunchoke Cheddar soup