This soup is vegetarian. Instead of using stock to make it, we make a quick asparagus broth using the asparagus and leek trimmings. The broth is delicate and fragrant and is the perfect way to make use of trimmings instead of throwing them away. This soup is completely guilt-free. It’s low in calories and has very little waste when it comes to the ingredients.
Trimmed stems from 2 pounds asparagus, roughly chopped
Green tops of 1 large leek, rinsed of sand and grit
1 medium carrot, chopped
1 garlic clove, halved
1 bay leaf
Salt to taste
1/4 teaspoon fresh ground pepper
9 cups water
2 tablespoons extra-virgin olive oil
1 leek, white and light green parts only, rinsed of sand and grit and sliced
1 garlic clove, minced
2 medium russet potatoes, peeled and diced (about 1 pound)
Salt to taste
6 to 7 cups asparagus broth (from recipe above)
2 pounds asparagus, woody ends trimmed and used for broth
3 cups baby spinach
Half of a lemon, cut into wedges
Fresh ground black pepper
Fresh shaved or grated parmesan cheese for garnish
In a large soup pot or Dutch oven, combine all of the ingredients for the broth and bring to a boil. Reduce the heat, cover and simmer for 25 minutes. Season to taste with salt bit by bit until you begin to taste the ingredients in the broth, but before it tastes salty. Strain.
Heat the olive oil in a large, heavy soup pot or Dutch oven over medium heat. Slice the leek then stir it as well as 1/4 teaspoon of salt into the hot oil. Cook, stirring often, until the leek has softened and smells sweet, about 5 minutes. Stir in the garlic and cook for one more minute.
Toss in the potatoes and pour in about 6 cups of the asparagus broth (save the remaining broth for thinning the soup later). Bring to a boil, reduce the heat then cover and simmer until the potatoes fall apart when pierced with a fork, about 20 minutes.
Meanwhile, cut tips from 12 asparagus spears 1 1/2 inches from the top. Reserve these for a garnish when serving. Roughly chop the rest of the asparagus.
When the potatoes are ready, stir in the chopped asparagus (not the reserved tips) and simmer until tender, but still bright green. Remove from the heat and stir in spinach until wilted, but still bright.
Blend the soup — it doesn’t need to be ultra-smooth, some texture is nice. An immersion blender makes quick work of this or use a blender. If you use a regular blender, it is best to blend in batches and not fill the blender as much as you usually would since the soup is so hot. Remove the center insert of the lid and cover it with a kitchen towel while blending — this helps some of the steam release and prevents the lid from popping off (which can be a big, hot mess).
Return the blended soup to the pot and heat through. Taste and adjust with additional salt and pepper. If the soup seems too thick, thin out with more asparagus broth a 1/4 cup at a time.
Just before serving, toss the reserved asparagus tips into an inch or two of boiling salted water and cook until tender, but still bright green, about 3 minutes. Rinse with cold water to stop the cooking.
Ladle the soup into bowls and garnish with two asparagus tips and parmesan cheese. Serve with a lemon wedge for squeezing over the top.