Cut tips from the asparagus 4cm from top and reserve. Chop the rest of the asparagus stalks into small rounds.

Melt the butter in a pot on medium heat. Add the onions and cook until translucent.

Add the broth, thyme sprigs, and bay leaf to the pot. Increase the heat to a boil, then reduce to a simmer.

Cook until asparagus are tender.

While the soup is cooking, blanche the asparagus tips in a small pot of boiling, salted water, until the tips are just tender. Drain. Rinse with cold water to stop the cooking. Keep aside.

Remove bay leaf and thyme sprigs and add chopped parsley.

Use stick blender to purée the soup.

Stir in the cream sour cream. Stir in the Cinzano and lemon juice. Season with salt and pepper to taste.Ladle the soup into bowls, then top each bowl with asparagus tips.