Heat the butter in a large pot over medium heat. Once melted, throw in the chopped onion and sauté until it turns translucent, about 5 minutes.

Stir in the minced garlic and cook for another minute without letting it brown.

Add the chopped asparagus (save a few tips for garnish if desired) and pour in the broth. Bring the mixture to a gentle boil before reducing it to a simmer.

Let the soup simmer for about 15-20 minutes until the asparagus is tender.

Using an immersion blender, puree the soup until smooth. If using a countertop blender, work in batches with caution.

Stir in the heavy cream (or coconut cream) and lemon zest, tasting for seasoning, and adjust with salt and pepper.