Drain the chickpeas and rinse them well under running water. If using dried beans, soak them overnight in plenty of water and then cook it until soft and mushy. You would use about 3 cups of cooked chickpeas.
In a pot, heat the olive oil and sauté the onions and celery until softened. Add the garlic and cook for a minute more.
Add the bay leaf, cumin powder, coriander powder and turmeric powder and stir.
Then add the vegetable broth, 1 cup of water and the chickpeas and stir. Let it simmer for about 20 minutes.
Remove the bay leaf and using an immersion blender, grind the mixture. You could leave it as chunky as you like or make it smooth. I went almost smooth with mine and reserved from chickpeas to garnish.
If using a blender, I would wait until the mixture cools down before processing it.
Return the soup to the pot and add the cayenne and salt to taste and let it come to a gentle boil. If the soup is too thick, add more water and bring it to the required consistency. I used about a cup more of water at this stage.
Ladle the soup into bowls and garnish with fresh mint leaves.