Mix meat with onions, salt and pepper. Form into tiny meatballs about the size of a cherry. Dust meatballs with flour. Bring broth to a boil. Lower in meatballs. Add chickpeas, carrots, tomato paste, bell pepper and cayenne. Simmer for 15 minutes. Add potato and rice. Cover and simmer for 20 minutes. Season with salt and pepper. Add cilantro. Ladle soup into bowls. Top with a dollup of yogurt and serve.