Cook the couscous in well-salted, rapidly boiling water until al dente.
While the couscous is cooking, sauté the onion and garlic in a large frying pan over medium heat - until sticky and jammy.
Drain the couscous and return to the pot. Toss through the sundried tomatoes, 2 tablespoons of the sundried tomato oil, fresh herbs and onion & garlic.
Place the chicken in a roasting dish and season generously all over, including inside the cavity, with salt & pepper. Stuff the chicken with about 1 ½ cups of the sundried tomato couscous. Truss the legs with twine. Drizzle the remaining sundried tomato oil all over the outside of the chicken.
Roast in the oven as per packet instructions. When the chicken has 20 minutes left of roasting time, brush over the sundried tomato pesto and continue roasting.
Place the remaining couscous salad on a large serving platter and sprinkle over the feta & extra fresh herbs.
Place the roast chicken on top so that the couscous can soak up any juices, and serve immediately, carving the chicken on top.
Tips for Roast Chicken with Sundried Tomatoes & Couscous: