Combine the oil, garlic and thyme, add the fish and mix together. Cover and marinate in the fridge for approx. 30 mins. Season the fish with salt shortly before cooking. Heat the oil in a large pan. Sauté the shallots, add the leek and fennel and cook for approx. 5 mins. Add the tomatoes, chilli and bay leaves, cook briefly. Pour in the stock and bouillon, bring to the boil, reduce the heat. Cover and simmer for approx. 15 mins. Add the fish and allow to infuse for approx. 5 mins. over a very low heat. Season the soup.
Mix the butter, tomato puree and garlic, season. Slice the baguette at intervals of approx. 1.5 cm but not all the way through. Spread the butter between the slices of bread. Transfer the baguette to a baking tray lined with baking paper.
Bake for approx. 10 mins. in the centre of an oven preheated to 200°C.