First, give the asparagus a good wash and pat dry, then peel thoroughly, saving all the peelings (no need to peel the tender tips!).
Trim about 1.5 - 2 cm off the woody stem ends, then slice the remaining stalks into roughly 3 cm pieces.
Peel the potato and cut it into small cubes.
Instructions:
Add the reserved asparagus peelings and woody ends to the mixing bowl and pour in 900 ml water. Add 1 teaspoon lemon juice, 1 teaspoon salt, 1 teaspoon sugar, and 10 g butter.
Place the chopped asparagus stalks and potato cubes into the simmering basket, then set the basket into the mixing bowl. Cook for 25 min / 100 °C / Speed 1. Cooking time may vary slightly depending on your water temperature; check for tenderness with a fork when done.
Remove the simmering basket and rest it over a bowl to drain. Pick out the delicate asparagus tips and set them aside for garnish.
Strain the asparagus stock through a sieve, pressing down firmly to extract all that delicious flavor. Reserve the liquid and set it aside.
Give the mixing bowl a quick rinse.
Add 40 g butter to the mixing bowl and melt for 1.5 min / 100 °C / Speed 1.
Add the flour and cook the roux for 2 min / 100 °C / Speed 1.
Pour in 700 ml of your reserved asparagus stock along with the heavy cream, and bring to a simmer for 5 min / 95 °C / Speed 1.
Meanwhile, sauté the reserved asparagus tips in a skillet with a touch of butter until tender and lightly golden.
Finally, add the cooked asparagus pieces and potato cubes to the mixing bowl and puree gradually for 20 sec / Speed 4–8 until smooth and velvety.
Season to taste with additional salt, black pepper, and lemon juice.
To Serve:
Ladle the warm soup into bowls, then top with the sautéed asparagus tips and chopped fresh chives. Enjoy!
Notes
For a lighter version, feel free to swap the heavy cream for light cooking cream.
Instead of sautéed asparagus tips, crunchy croutons make a wonderful garnish!