Asparagus Soup with Lemon and Parmesan

Bahan-bahan (4 porsi)

• 2 bunch es asparagus ((about 2¼ pounds/1 kg), bottom ends trimmed)
• 3 tablespoons unsalted butter
• 2 medium yellow onions, (chopped)
• 3 cloves garlic, (peeled and smashed)
• 6 cups low-sodium chicken broth
• Salt
• Freshly ground black pepper
• 2 tablespoons freshly squeezed lemon juice, (from one lemon)
• ½ cup shredded Parmigiano-Reggiano
• Handful fresh herbs, (such as thyme, dill or basil (optional, for garnish))