Brown and season ground beef. Cook riced cauliflower. Drain well. Heat in dry pan until slightly toasted. Season with cumin and chili powder.
Combine beef, cauliflower and beans. Pour into 9x13 inch baking dish. Stir in cheese. Press down. Bake for 20 minutes or until heated through and bubbly. Let cool.
Cold toppings Assembly:
Spread sour cream across slightly cooled casserole. Sprinkle additional toppings evenly over casserole. Serve immediately.