Lemony Vegetable Cous Cous

Slightly modified from Ethnic Cuisine by Lorraine Turner.
Ingredients:
2 Tbsp. vegetable oil
1 large onion, coarsely chopped
1 carrot, chopped
1 turnip, chopped
2 1/2 c. vegetable stock
1 scant c. couscous
2 zucchini, chopped
2 red bell peppers, seeded and chopped
1 scant c. green beans, chopped
Grated rind of 1 lemon
Pinch of ground turmeric (optional)
1 Tbsp. finely chopped fresh cilantro or parsley
Salt
Pepper
Fresh flat-leaf parsley sprigs, to garnish

Heat the oil in a large pan over medium heat. Add the onion, carrot, and turnip and cook, stirring frequently, for 3-4 minutes. Add the stock and bring to a boil. Reduce the heat, then cover and simmer for 20 minutes.
Meanwhile, prepared the couscous according to the instructions on the package.
Add the zucchini, red bell pepper, and green beans to the pan and stir. Simmer the vegetables for 8-10 minutes.
Stir the lemon rind into the couscous, then add the turmeric (if using) and mix thoroughly.
Season the couscous to taste with salt and pepper, then pile onto warmed serving plates. Ladle the vegetables and some of the liquid over the top. Scatter over the cilantro and serve immediately, garnished with parsley sprigs.
Serves 4.