Heat the olive oil in a large soup pot over medium heat. Add the garlic and onion and cook 304 minutes, until soft and fragrant. Add the carrots and celery and cook 5-7 minutes, until beginning to soften.

Stir in all but 1/4 cup of the chickpeas and all of the chicken broth; add the whole sprigs of rosemary to the pot. Bring to a boil, then reduce the heat and simmer for 15-20 minutes, or until the vegetables are soft.

While the soup cooks, cook the bacon in a skillet set over medium heat for 6-8 minutes, or until crisp. Drain on paper towels, then crumble.

Transfer the soup to a blender, working in batches if needed. Blend 40-60 seconds, or until the soup is smooth. Return the soup to the pot and season to taste with salt and pepper.

Serve the soup topped with crumbled bacon, fresh herbs, and reserved chickpeas.