2) Dissolve the cornflour in the water. Bring the red pepper concentrate to the boil in a saucepan, then whisk in the cornflour mix a little at a time until thickened. Turn off the heat and whisk in the butter, 1 tablespoon at a time. Season with salt and pepper.
3) Remove the prawns and scallops from the marinade and discard the marinade. Cook the prawns and scallops on the charcoal griddle or barbecue for a couple of minutes on each side or until just cooked through.
Serve immediately with the sauce, garnished with sliced red peppers, spring onions and chive oil.