Put on a saucepan with water, salt, sugar and a piece of butter and bring the water to a boil. In the meantime, peel the asparagus and cut off the ends. Then add the asparagus to the boiling water and cook for about 12 minutes until al dente. Cooking time may vary depending on the thickness of the asparagus. Lift the asparagus out of the water and divide it on three plates. Pour lemon juice, flakes of butter, pepper and grated Parmesan on top. If you want to eat the asparagus as a main course, then prepare twice the amount of the recipe and serve boiled potatoes with it.