Place spices, garlic, zest, juice and 2 tablespoons in a large bowl and whisk to combine. Season to taste. Add steak and coat well in marinade. Cover and marinate at room temperature for 30 minutes.
Preheat oven to 200C. Meanwhile, place pumpkin on a large shallow oven tray and drizzle with remaining oil and season to taste. Roast for 25 minutes or until golden and cooked. Bring a large saucepan of boiling water to the boil, add brocolini and cook for 5 minutes or until cooked to your liking. Drain and season to taste.
Preheat a lightly greased char-grill pan or barbecue to high. Cook steak for 2½ - 3 minutes each side or until cooked to your liking. Rest for 15 minutes, covered with foil in a warm place, before slicing, to serve
To make herbed couscous, place couscous in a large heatproof bowl and stir through olive oil. Bring stock to the boil and stir into couscous. Cover and stand for 10 minutes. Using a fork, gradually loosen couscous then stir in remaining ingredients. Season to taste.
Divide couscous, brocolini, pumpkin and flank steak among plates. Serve with lime wedges.
If time permits, marinade steak for 3 hours or over night in the refrigerator. Before cooking, leave to stand at room temperature.
This popular cut is best cooked using high temperature methods.
Sirloin steaks can also be thinly sliced to be used in stir-fries.
Also known as Porterhouse Steak, New York Steak or Striploin Steak.
Other substitutes are flat iron steak or rump medallion.
For best results, ask your butcher to cut your steaks at about 3-4cm thick steaks