In a large stock pot over medium heat, melt butter. Add onion and garlic and sauté for 1-2 minutes until onions are translucent and tender. Add asparagus, lemon juice, and chicken/vegetable broth. Bring to a boil, then reduce to a simmer and cook for 10-15 minutes until asparagus is very tender.

Transfer to a blender and puree until smooth. Transfer back to stock pot.

Add milk, cheese, salt, and pepper and stir until cheese is completely melted and incorporated. Serve with additional parmesan cheese as desired - enjoy!