Peel and finely dice the garlic and onion. Wash and clean the fennel and cut into small cubes. Wash the tomatoes. Cut 2 tomatoes into small cubes. Chop anchovies and olives coarsely
Heat 2 tablespoons of oil in a saucepan. Brown the onions and fennel for about 5 minutes. Add tomatoes and garlic to the fennel and simmer for about 10 minutes until a relatively "dry" mass is formed. Add olives and anchovies, season with salt and pepper
Wash the marjoram, shake dry and pluck off the leaves. Coarsely chop half of the leaves. Add the chilli and marjoram to the vegetables and season again
Cut 1 tomato into thin slices. Wash the fish, dab dry and cut into 2 equal pieces. Cut each piece in half horizontally, season with salt and pepper
Put half of the tomato slices and vegetable mixture on one half. Place the second half on top. Spread the remaining tomato slices on top and tie them together with kitchen string. Put fish parcels in an ovenproof dish and drizzle with 2 tablespoons of oil. Cook in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for approx. 20 minutes. Take the fish parcels out of the oven and cut them in half. Garnish with marjoram leaves and serve immediately