1. For the vinaigrette, bring the sherry vinegar to the boil in a pan. Add the parsley, sultanas, olive oil, pine nuts, diced tomatoes and remove from heat. Season to taste.
2. For the soup, place the onions, rosemary and potatoes in a saucepan with the fish stock. Bring this to the boil and simmer for 15 minutes until cooked. Remove from the heat and blend with the Braun Multiquick 7 hand blender in the pan until smooth.
3. Blend the olive oil into the potato mixture the pan.
4. For the cod, heat the oil in a frying pan and season the fish fillets. When the oil is hot add the fillets, skin side down and cook for 1-2 minutes until the skin becomes golden. Turn over and cook for a further minute. Remove the fillets and finish cooking in an oven for about 5 minutes at 180°C or until done to your liking.
5. Divide the fish fillets in the middle of four bowls and spoon over vinaigrette. Pour warm potato, rosemary and olive oil soup around the outside.