- 2 tablespoons butter
- 1 onion, finely diced
- salt to taste
- 4 cups chicken broth
- 2 cups water
- 2 pounds fresh asparagus, trimmed and cut into 1-inch pieces
- 1 pinch cayenne pepper, or to taste
- freshly ground black pepper to taste
- 1 pinch ground nutmeg
- 1/2 cup heavy whipping cream
- Cream Topping:
- 1/4 cup heavy whipping cream (optional)
- 1 tablespoon freshly grated Parmigiano-Reggiano cheese
- 1 teaspoon lemon zest (optional)
- 1 pinch cayenne pepper (optional)
- Melt butter in a soup pot over medium heat. Add minced onion and salt; cook and stir until onion is soft and golden, about 10 minutes.
- Pour chicken broth and water into pot. Bring to a boil, reduce heat to medium, and simmer 15 minutes.
- Place asparagus pieces in simmering broth. Cook, stirring occasionally until asparagus is just tender and still bright green, 5 to 10 minutes. Remove from heat.
- Use an immersion blender to blend soup until smooth, about 3 minutes.
- For a finer texture, strain soup through mesh strainer. Return strained soup to pot and place on stove.
- Turn heat to low. Season with cayenne pepper, black pepper, and nutmeg. Adjust salt to taste. Whisk 1/2 cup cream into soup.
- Place 1/4 cup cream, Parmigiano-Reggiano cheese, and lemon zest in a small bowl. Whisk until frothy and slightly thickened, about 1 minute.
- Ladle soup into bowls. Drizzle a spoonful of Parmigiano-Reggiano-lemon cream on top of each serving and swirl to form a random design.
- Sprinkle with a pinch of lemon zest and cayenne pepper, if desired.