Place the couscous in a bowl, crumble in the stock cube and stir well. Add the measured water, stir, then cover and set aside, while preparing and cooking the vegetables, to soak and swell.
Put all the prepared vegetables into a large roasting tin and drizzle over 3 tablespoons of the oil and toss to coat lightly. Roast in a preheated oven, 200°C (400°F), Gas Mark 6, for 30–35 minutes until the vegetables are soft and lightly charred.
Lightly fork the soaked couscous to fluff it up, then drizzle over the remaining oil and toss well. Add the warm vegetables, parsley or basil and pine nuts and toss well before serving.