Place potatoes at the bottom of a stick free sauce pan.
Place all other ingredients scattered carefully on top of the potatoes- fish, onions, carrot, tomatoes, garlic, Portuguese spice, Piri-piri, salt to taste.
Spread out the olive oil and Tawny over all the food to cover the top.
Bring to a fast hot boil, then shuffle gently with a spatula from the side to the middle, without stirring, to bring some of the juices to the bottom of the pan.
Switch to low, and leave to cook for 40 min.
Spoon to a serving dish, and decorate with Basil leaves, olives and Harissa.