Gather your ingredients. You'll need chickpeas (canned or cooked from dry), vegetable broth, onion, garlic, carrots, celery, lemon, olive oil, cumin, coriander, salt, pepper, and fresh parsley for garnish.
Heat olive oil in a large pot over medium heat. Add diced onion, minced garlic, chopped carrots, and celery. Sauté until the vegetables are softened and fragrant, about 5-7 minutes.
Add the chickpeas to the pot along with ground cumin and coriander. Stir well to coat the chickpeas and vegetables with the spices.
Pour in the vegetable broth, stirring to combine. Bring the soup to a simmer, then reduce the heat to low and let it cook for about 15-20 minutes to allow the flavors to meld together.
Season the soup with salt and pepper to taste. Adjust the seasoning as needed, keeping in mind that the lemon juice will add brightness and acidity to the soup.
Squeeze fresh lemon juice into the soup, starting with the juice of one lemon. Taste and add more lemon juice if desired, depending on your preference for acidity.
Let the soup simmer for an additional 5 minutes to allow the lemon flavor to infuse into the broth and chickpeas.
Ladle the lemony chickpea soup into bowls and garnish with freshly chopped parsley. Serve hot, optionally with a slice of crusty bread or a sprinkle of grated Parmesan cheese on top.