Creamy Celery Root and Sweet Onion Soup

Melt butter in a Dutch oven over medium-low heat. Add celery root, onion, thyme, and garlic. Cover and cook 25 minutes, stirring occasionally.

Add stock, water, salt, and rind. Bring to a simmer; cover and cook at low 20 minutes or until very tender. Discard rind.

Add bread. Stir with a wooden spoon, scraping bottom of pan.

Pour half of soup in a blender. Remove center piece of blender lid (to allow steam to escape); secure lid on blender. Drape a clean towel over opening in lid (to avoid splatters). Blend until smooth; pour into a large bowl. Repeat with remaining soup. Return pureed soup to pan.

Stir in buttermilk; heat over medium-high heat until very hot (do not boil). Top soup with crème fraîche and chives.

Variation: Creamy Garlic Soup: Sub 4 cups garlic cloves for celery root (omit the 8 cloves). Decrease onion to 2 cups; add 1 cup cubed peeled potato. Increase salt to 3/4 teaspoon. Add 1 1/2 tablespoons sherry at end; omit crème fraîche and chives. Top with a mixture of 1/3 cup toasted breadcrumbs, 2 tablespoons grated pecorino Romano, 1 tablespoon parsley, and 2 teaspoons lemon rind. Serves 12 (serving size: about 3/4 cup soup and about 2 teaspoons topping) CALORIES 105; FAT 8g (sat 1g); SODIUM 219mg