In a large pot, combine raw chickpeas with enough water to cover them by at least two inches; add the whole onion. Bring to a boil, then reduce to a simmer and cook for about 2 hours until tender.

In the same pot over medium heat, add a splash of olive oil, then stir in minced garlic, sautéing for 2-3 minutes until golden and fragrant.

Pour in crushed tomatoes, return cooked chickpeas to the pot, adding reserved cooking water as needed. Simmer for at least 30 minutes.

Remove from heat and stir in lime juice, add chopped parsley and cilantro, adjusting seasoning with kosher salt as needed.

Ladle soup into bowls, garnishing with additional herbs and chili flakes, and serve with crusty bread or salad.