Heat the olive oil in a large pot over medium heat. Add the chopped onion and cook until softened, about 5 minutes.
Add the minced garlic, diced carrots, and celery to the pot. Cook for another 5 minutes, or until the vegetables are tender.
Stir in the ground cumin, ground coriander, and smoked paprika, and cook for 1 minute to toast the spices.
Pour in the vegetable broth, chickpeas, and diced tomatoes. Bring the soup to a simmer, then reduce the heat to low and let it simmer for 20-25 minutes to allow the flavours to meld together.
Use an immersion blender to blend part of the soup until smooth, leaving some chickpeas and vegetables intact for texture. Alternatively, transfer a portion of the soup to a blender and blend until smooth, then return it to the pot.
Season the soup with salt and pepper to taste. If the soup is too thick, you can add more vegetable broth or water to reach your desired consistency.
Serve the vegan chickpea soup hot, garnished with freshly chopped parsley or cilantro.