Tamarind Chickpea Soup

I was so inspired by this recipe from Orangette's blog for a Tamarind Chickpea soup - a great combination, as she describes, of Indian and Italian flavors mingling together. I made a couple of additions and subtractions - added in some yams since I love those in curries and figured they would contribute a nice sweetness and color to the soup. I also cooked chickpeas from scratch to go in the soup and added kale instead of chard, as it tends to hold up better in leftovers. My soup became more like a stew over time - not much liquid, so it might be better to increase the amount of broth even more - to 4 cups or just enjoy it as is. It was excellent served with cumin-seed pappadums and mint-cilantro sauce; also excellent served over rice if you want to stretch the dish even farther.

Tamarind Chickpea Kale Soup (use a LARGE pot)
1 c. dried chickpeas, soaked overnight and cooked beforehand. (Alternately use 2 15-oz cans chickpeas, well-rinsed)
3 medium yellow onions, coarsely chopped
2 medium zucchini, halved lengthwise and cut into 1/3-1/2" thick hemispheres
2 - 3 sweet potatoes or yams, peeled, and chopped into ~ 1/2" cubes (or something cube like)
10 large leaves kale, ribs removed, coarsely chopped
4-5 large cloves garlic, coarsely chopped
3/4 c. minced cilantro leaves
2 - 4 Tbs ground cumin
2 - 4 Tbs curry powder (I used madras)  
1 - 3 Tbs ground coriander
2 Tbs sweet paprika
2 Tbs dry basil (I used Thai lemon basil)
1 28-ounce can chopped tomatoes (including juice)
1/3 cup red wine vinegar (or apple cider vinegar)
1/4 c. tamarind paste  (I had dried tamarind pulp which I soaked in hot water and pressed through a strainer-- likely easier to just buy the paste)
1 - 2 Tbs packed brown sugar
3 cups vegetable broth
Water
Salt, to taste
Pepper, to taste
Red pepper flakes, optional

1. Heat the soup pot on medium heat with olive oil. Add in the onions, zucchini,  and kale and saute, stirring occasionally for 8-10 minutes.
2. Add the garlic, cilantro, and dried spices (including salt and pepper). Cook for another minute or two.
3. Stir in the tomatoes, chickpeas, sweet potatoes, vinegar, tamarind, brown sugar, and broth. (If it seems like you need more liquid to cover the veggies/chickpeas, you can add a bit more broth or water). Bring the soup just to a boil, and reduce the heat to simmer. Cook for about 1 hour, adding water if necessary.
4. Adjust for seasoning. If you like, add a bit more tamarind (I definitely did this), salt, or pinches of red pepper flakes. When the veggies are tender/the flavors complete, remove and serve with pappadums, mint cilantro sauce, or rice.