Preheat barbecue to high, keeping one element off. Remove some of the excess skin at the ends of each breast, then make incisions in a checkerboard pattern on the skin, without piercing the flesh. Season with salt and pepper to taste. Set aside.
Place the cauliflower steaks (slices) on a large tray and drizzle with oil, then season each side with salt, pepper and turmeric. Set aside.
Place the turmeric cauliflower slices on the barbecue grill. Do the same with the duck breasts over direct fire, and sear for 1 ½ to 2 minutes skin side down on the grill, turning once. Continue cooking the breasts over indirect heat for another 8 to 10 minutes with the skin side down, and then finish cooking over direct heat for a final 2 minutes, flesh side Down. Keep an eye out for flare ups. If this happens, move the meat around and turn it over.
Flip the cauliflower steaks halfway through cooking.
Remove the breasts from the grill and set aside for 5 minutes, loosely covered with a sheet of aluminum foil.
Slice the breasts on the diagonal into thick slices and serve immediately with the turmeric cauliflower steaks. Serve with herb toast and white rice on the side.
