Give your asparagus spears a good wash.
Snap the tough ends off the asparagus spears and discard.
Add butter in a medium saucepan, then add the spring onions and asparagus spears.
Saute for around 10 minutes.
Add the beef or chicken broth.
Cook at a lively simmer for 5 minutes.
Add thickened cream and any extra seasonings.
Simmer for a couple of minutes.
Remove from the heat and Purée in a food processor until smooth.
Strain the purée through a sieve back into the saucepan.
Rubbing the mixture through with a flexible scraper or wooden spoon and leaving any fibrous parts in the sieve.
Discard the contents of the sieve.
Reheat gently over low heat, making sure not to let the soup boil.
Ready to serve.
To serve, top the soup with a swirl of cream, a sprinkle of Parmesan cheese and some freshly cracked black pepper.
For an added kick, add a few drops of fresh lemon juice to your bowl before serving.
Important!
Don't be tempted to omit the final straining of the soup!
If you leave the bits of fibrous asparagus skin in the soup, they give it a very unpleasant texture.
Use a sieve with a medium mesh, not too coarse and not too fine: too coarse will let too much of the fibre through, too fine will make the job of straining too difficult.