Place a medium size soup pot over medium low heat and when it is hot, add the oil. Add the onion, garlic, ginger and zucchini and cook until the onion is golden and the zucchini is almost tender, 10- 15 minutes.

Stir well, add the curry and rice and cook 10 minutes. Add the stock and bring to a boil. Lower the heat to low and cook, covered, until the rice is tender, about 30 minutes.

Remove the solids and place in a food processor or blender. Process until completely smooth, gradually adding remaining broth, basil or cilantro and yogurt.

Serve immediately, or cover and refrigerate up to three days. Serve hot or chilled.