Preheat oven to 400°F (200°C). Cut the top off the garlic head, drizzle with 1 tablespoon olive oil, wrap in foil, and roast for 30-35 minutes until soft.
- Toss chickpeas with remaining olive oil, salt, pepper, and cumin. Spread on baking sheet and roast for 20-25 minutes until crispy.
- Heat a little olive oil in a large pot over medium heat. Add diced onion and sauté until translucent, about 5 minutes.
- Pour in vegetable broth and add lemon zest. Bring to a simmer.
- Squeeze roasted garlic cloves out of skins and add to pot with roasted chickpeas (reserve some chickpeas for garnish). Simmer for 5 minutes.
- Use immersion blender to puree soup to desired consistency.
- Stir in fresh lemon juice and adjust salt and pepper to taste.
- Ladle soup into bowls and garnish with reserved roasted chickpeas and fresh herbs.