Cook the moong dal in water (not included in ingredients) in a saucepan over medium heat until tender, but the lentils are still separate. Drain.
In a dutch oven or other large soup pot, fry the ground beef over medium heat.
Puree the onion in 1 cup water in a blender or food processor and add to the ground beef.
Add garlic and salt also to the meat and stir-fry for about 10 minutes.
Add the tomato paste and 1 more cup water and simmer 10 more minutes.
Add the kidney beans, chickpeas, moong dal, ground coriander, black pepper, cayenne powder, and 6 cups water. Stir and simmer for 20 more minutes.
Check to see if 1/4 -1/2 teaspoon more of salt is needed.
Turn off heat.
In a blender put the yogurt, 1/2 cup water, flour and cornstarch and puree.
After the soup has cooled slightly stir in the yogurt mixture. Do not boil the yogurt or it will curdle. Sprinkle with dried mint. Serve with naan or pita bread.