Pick and blanch basil leaves. Refresh in iced water immediately. Dry thoroughly and place in a food processor. Add a little olive oil and puree. Scrape basil from sides of the jug and add more oil. Season with salt and pepper and place in a small saucepan. Place on the flat top or over a low flame and cook for 1/2 hour. Pass through a fine strainer pressing well to extract maximum flavor. Add finely chopped tomato concasse, chopped black olives, and chopped basil and chives. Finish with 1 tablespoon Balsamic vinegar.
For the marmalade, cook red peppers under a preheated grill until blistered and well charred on all sides. Place in a bag and leave until cool enough to handle, then peel, deseed and cut into small dice. Heat the oil in a pan, add the onion and sweat until soft and translucent. Add the garlic and sweat for another minute. Add red peppers, chili, and sugar and sweat for 2 minutes. Add the red wine vinegar and boil until reduced by half. Stir in the stock, reduce the heat and simmer until very thick. Add the tomatoes and cook for 3 minutes, stirring frequently. Keep warm.
To assemble the dish, season the fish with salt and pepper, coat with olive oil and in a very hot grill pan, mark the fish and then transfer to baking tray. Cook in a preheated 200 degree oven for 4 minutes. Remove the fish and let rest for 1 minute. Place a bit of the red pepper marmalade in the center of a plate. Place the fish on top, and arrange some of the herb salad on top of the fish. Drizzle the basil oil and balsamic around the plate. Serve immediately.
For the Herb Salad: Combine the vinegar, lime juice and olive oil and toss in the herbs, season with salt and pepper. Set aside.