In bowl, mix beef, rice, 1 onion and garlic. Season to taste with salt and pepper. Shape mixture into small balls, frequently soaking your hands in water. Set aside.
In large saucepan, sauté meat balls, remaining onion, green pepper and zucchini in butter for 7 to 8 minutes. Stir in broth, tomatoes and black beans.
Bring to a boil.
Add chili powder and cumin and season to taste with salt, pepper and hot pepper sauce. Reduce heat, cover and simmer for 45 minutes.
Serve in soup bowls and garnish with fresh coriander and 1tbsp (15 mL) sour cream. Top with Marble Cheddar cheese. Serve with nachos.