Boil the potatoes in the water until very soft and then drain, reserving the cooking liquid. In a blender, combine the potatoes with about 1 cup of the cooking liquid or stock and puree; then transfer to a soup pot. Combine the chickpeas, mint and about 2 cups of the cooking liquid and/or stock and blend until very smooth. Add the chickpea puree to the soup pot and heat gently, stirring frequently.
Meanwhile, in a skillet, heat the oil and sautÃ© the onions, garlic, salt, cumin, coriander, turmeric, cayenne and black pepper until the onions are translucent, about 10 minutes. Stir the sautÃ©ed onions into the soup. If the soup is too thick, add more cooking liquid, water or stock. When the soup is hot, stir in the diced tomatoes and cook for a few more minutes. Add more salt and black pepper to taste.
Serve topped with parsley and offer lemon wedges on the side.
Makes about 10 cups per recipe. 3 Points per cup.