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