Firstly, I prepare the asparagus to cook them. To do that, I cut a little bit on the end of the stem to take off the fibrous end. About 1/2 an inch.
Then, I put enough water to boil with a spoonful of coarse salt. Once it's bubbly, I add the asparagus to be cooked. To know if they are ready, be sure they are shiny green and still crunchy but tender. I think that's the way they are perfect.
To make the soup, I blend the asparagus with a bit of their cooking liquid, and if necessary, I add a little fresh water. Remember your cooking liquid is salty. The amount of water will depend on the texture you want for your soup. I like it quite thick, honestly.
Lastly, I add a little bit of butter, freshly ground pepper and verify seasoning. If necessary, I adjust as necessary.
When serving it, I add a little freshly ground parmesan cheese. Simply delicious, I promise.