For soup:
1 medium leek (white and pale green parts only), chopped
1 medium russet (baking) potato
1/2 cup chopped shallot
2 tbsps unsalted butter
1 tbsp. olive oil
2 bunches Chinese celery (1 1/2 lb total), top leaves discarded and stalks cut into 2-inch pieces
1/2 cup dry white wine
4 cups chicken stock or low-sodium chicken broth (32 fl oz)
1/2 cup heavy cream
1/2 tsp. salt
1/4 tsp. black pepper
For croutons:
6 (1/4-inch-thick) diagonal baguette slices
1/4 cup extra-virgin olive oil
Kosher salt to taste
Fresh Chinese parsley leaves or flat-leaf parsley leaves for garnishing

Creamy Chinese Celery Soup

1. Wash leek well in a bowl of cold water, then lift out and drain well. Peel and chop potato.
2. Cook shallot in butter and oil in a 3-quart heavy saucepan over moderate heat, stirring, until softened, for about 2 minutes. Add leek and cook, stirring, until softened, for about 5 minutes.
3. Add celery and potato and cook, stirring, for 2 minutes. Add wine and boil for 1 minute. Add broth and simmer, covered, until celery is very tender, for about 1 hour.
4. Purée soup in batches in a blender until very smooth (use caution when blending hot liquids), then pour through a large medium-mesh sieve into a bowl, pressing hard on solids. Discard solids.
5. Transfer soup to cleaned saucepan, then stir in cream, salt, and pepper and heat over low heat until hot. Thin with water if desired.
6. Make croutons while soup simmers: Preheat oven to 350°F. Brush baguette slices with oil and season generously with kosher salt and pepper. Arrange in 1 layer on a baking sheet, then bake in middle of oven until golden brown and crisp, for about 12 to 15 minutes.
7. Serve soup topped with croutons.
8. Tip: Soup can be made 1 day ahead and cooled, uncovered, then chilled, covered. Croutons can be kept in an airtight container at room temperature for 2 days.
   Makes 6 servings
   Preparation time: 1 hour 30 minutes