Wash and peel the asparagus, reserving the peels. Chop the spears into 2-3 cm pieces.

In a medium saucepan, boil 1 liter of water and add the asparagus peels. Simmer for about 20 minutes.

In a large pot, melt 2 tablespoons of butter over medium heat and add 2 tablespoons of flour, stirring continuously for 1-2 minutes.

Gradually strain the broth into the roux, stirring constantly to avoid lumps. Cook until thickened, about 3-5 minutes.

Add 500 ml vegetable broth and the chopped asparagus pieces. Simmer for about 12 minutes until tender.

Stir in 200 ml of cream, season with salt, pepper, lemon juice, and nutmeg. Adjust seasoning as needed.

Ladle into bowls, garnish with parsley and chervil if desired, and serve warm.