Heat oil in a soup pot and saute'' the onion and garlic until the onion is tender. Add the curry powder, cumin and tumeric, and cauliflower and stir together for a minute or two. Add the stock or bouillon and the potato and bring to a boil. Cover and reduce heat, and simmer 30 minutes.
2. Puree'' in a blender or food processor in batches. Return to the pot and adjust the seasonings, adding salt, pepper, curry powder or cumin to taste. Heat through.
3. Stir together the yogurt and cornstarch
