To save time, use canned chickpeas instead of dried.
- 1 1/2 cups dried chickpeas, or 3 15-ounce cans chickpeas, rinsed
- 2 large onions, coarsely chopped
- 1 bunch broccoli, stems reserved for another use, cut into small florets t
- Flat-leaf parsley and fresh tarragon leaves (for garnish)
If using dried chickpeas, place in a medium bowl and add cold water to cover by 2-inch. Let soak overnight in refrigerator. Drain chickpeas.
Heat oil in a large heavy pot over medium heat. Add onions, garlic, and thyme sprig; cook, stirring occasionally, until onions are soft, 10-15 minutes. Add chickpeas and wine. Bring to a rapid simmer; cook until wine is reduced by half, about 2 minutes. Add broth and bring to a boil. Reduce heat, cover, and simmer until chickpeas are very soft, 1 1/2-2 hours for dried chickpeas, or about 30 minutes for canned. Discard thyme sprig.
Working in batches, purée chickpea mixture in a blender or with an immersion blender, adding water by 1/2-cupfuls if needed, until smooth. Season with salt. DO AHEAD: Chickpea soup can be made 1 day ahead. Let cool; cover and chill.
Meanwhile, cook broccoli in a large pot of boiling salted water until crisp-tender, about 4 minutes. Drain; rinse under cold water.
Reheat soup. Divide soup among bowls and garnish with broccoli and herbs.