Finely dice the onions and cut the zucchini into small pieces. First quarter lengthways, then cut into slices. Heat the olive oil in a pan and fry the onions until translucent. Add the zucchini and fry for about 6 - 8 minutes. Season the zucchini with salt and pepper and possibly a little curry.
Meanwhile, bring the water to the boil with the vegetable stock, turmeric, cinnamon, paprika powder, curry and a dash of olive oil. Add the couscous, remove the pan from the plate and let the couscous steep for 5 - 8 minutes. Then add the butter and stir well.
For the yogurt sauce, season the yogurt with lemon juice, oregano, basil, salt and pepper. Serve the couscous with the zucchini and garnish with the yogurt sauce.