01 - Heat the olive oil or butter in a large pot over medium heat. Add the chopped onion and sauté until soft and translucent, approximately 4 minutes.
02 - Add the minced garlic and cook for 1 minute until fragrant, being careful not to brown it.
03 - Stir in the diced potato and asparagus pieces. Sauté for 3–4 minutes to develop flavor.
04 - Pour in the vegetable broth. Bring to a boil, then reduce heat and simmer uncovered for 15–20 minutes until all vegetables are very tender.
05 - Remove from heat. Using an immersion blender, puree the soup until completely smooth and velvety. Alternatively, transfer carefully to a countertop blender in batches.
06 - Return the soup to low heat. Stir in the heavy cream, lemon zest, and lemon juice. Heat gently until warmed through, but do not allow to boil.
07 - Season to taste with additional salt and black pepper as needed. Ladle into serving bowls and garnish with fresh chives or dill.