Chef John's Cream of Asparagus Soup - Recipook

Ingredients

• 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
• 0.5 cup heavy whipping cream
• 0.25 cup heavy whipping cream
• 1 tablespoon freshly grated Parmigiano-Reggiano cheese
• 1 teaspoon lemon zest
• 1 pinch cayenne pepper