Prepare the asparagus by trimming and cutting into pieces.
In a large pot, heat olive oil or butter over medium heat.
Add chopped onion and sauté until translucent.
Add minced garlic and cook for an additional minute.
Stir in the asparagus pieces and sauté for a few minutes.
Pour in the vegetable broth and bring to a boil.
Reduce heat and simmer until the asparagus is tender.
Remove from heat and blend until smooth.
Return the blended soup to low heat and stir in heavy cream.
Season with salt and pepper to taste, and add lemon juice if desired.
Serve immediately, garnishing if desired.