2 pounds sunchokes
3 tablespoons butter
1 cup chopped onion
1 cup chopped leek (white and pale green parts only)
2 cloves garlic, chopped
7 cups (or more) vegetable broth
1/2 cup heavy whipping cream
Ground white pepper
Shelled and roasted pumpkin seeds
Rinse and scrub sunchokes to remove all soil. Melt butter in heavy large pot over medium heat. Add onion, leek, and garlic; sprinkle with salt and sauté until soft and translucent, stirring often, about 12 minutes. Cut sunchokes into 1-inch pieces. Add to onion mixture and sauté 5 minutes. Add vegetable broth, increase heat to high, and bring to boil. Reduce heat to medium-low, cover, and simmer until chokes are very tender, about 1 hour. Cool slightly.
Working in batches, puree soup in blender until very smooth. Return to pot. Rewarm soup, adding more broth by 1/4 cups, if needed, to thin. Stir in cream and season to taste with salt and white pepper.
This soup can be made 1 day ahead and refrigerated. Rewarm before serving. Divide soup among bowls and garnish with toasted pumpkin seeds; top with a drizzle of pumpkin seed oil and some sautéed mushrooms, if desired.
Recipe adapted from epicurious.com.