Carefully peel the asparagus, remove the woody parts and boil 2 liters of water with salt, sugar and butter. Put the asparagus in and cook at 95 °C for 10 minutes. Lift out the asparagus, put it into the boiling, lightly salted sweet cream and let it simmer at 95 °C for another 10 minutes. As soon as the asparagus is cooked, lift out and keep warm. Reduce the sweet cream by half (boil down). Season with salt, grated nutmeg, ground pepper, a little lemon juice and grated lemon zest. Stir a little cornstarch with a little water until smooth and thicken the sauce slightly with it. Arrange the asparagus and pour the finished sauce over it.