Steps
- Melt 2 tablespoons of unsalted butter in a saucepan over medium heat. Stir in ¼ cup of all-purpose flour; cook over low heat for 3 minutes.
- Gradually whisk in 4¼ cups of cooled vegetable stock. Bring to a boil and cook for 10 minutes, stirring until smooth.
- Lower the heat and stir in 3 tablespoons of coarse mustard. Season with salt and pepper; keep below a boil.
- Add 100g of green asparagus tips and cook gently for 4 minutes, until just tender.
- Ladle into bowls and add 100g of thinly sliced smoked salmon. Finish with ¼ cup of sour cream.