- 2 bunches asparagus about 2-1/4 pounds, bottom ends trimmed
- 3 tablespoons unsalted butter
- 2 medium yellow onions chopped
- 3 cloves garlic peeled and smashed
- 6 cups low-sodium chicken broth
- Freshly ground black pepper
- 2 tablespoons freshly squeezed lemon juice from one lemon
- 1/2 cup shredded Parmigiano-Reggiano
- Handful fresh herbs such as thyme, dill or basil (optional, for garnish)
- Melt the butter in a large pot over medium heat. Add the onions and garlic and cook, stirring frequently, until soft and translucent, about 8 minutes. Do not brown; reduce the heat if necessary.
- In the meantime, cut the tips off of one bunch of the asparagus and set aside (you’ll use those for a garnish). Cut the remaining spears and the other bunch of asparagus into 1/2-inch pieces.
- Add the chopped asparagus to the pot (minus the reserved tips), along with the chicken broth, 1 teaspoon salt and 1/4 teaspoon pepper. Bring to a boil, then cover and turn the heat down to low. Simmer for about 30 minutes, or until the vegetables are very tender.
- Meanwhile, bring a small pot of salted water to a boil. Cook the reserved asparagus tips for a few minutes, or until tender-crisp. Drain the tips and then place them in a bowl of ice water to “shock” them — this stops the cooking process and preserves their bright green color. Once the tips are cool, drain them and set aside.
- Purée the soup with an immersion blender until completely smooth. (Alternatively, use a standard blender to purée the soup in batches, then return the soup to the pot.) Bring the soup back to a simmer and stir in the lemon juice and Parmigiano-Reggiano. Taste and adjust seasoning, if necessary. To thicken the soup, allow it to simmer, uncovered, until the desired consistency is reached.
- Ladle the soup into bowls, then top each bowl with asparagus tips, Parmigiano-Reggiano, herbs (if using), and freshly ground black pepper.