Drain the cheese mixture. Collect the oil. Halve the zucchini, scrape out the inside with a ball cutter or a teaspoon. Crush the inside. Peel onion and chop finely.
Clean, wash and finely dice the aubergine. Wash, clean, quarter and seed the tomatoes. Cut the flesh into small cubes. Cut ciabatta into cubes. Heat 2 tablespoons of drained oil in a pan.
Roast the ciabatta in it until golden brown all around. Season with salt and pepper. Heat 1 tablespoon of oil in another large pan. Fry the zucchini halves for about 3 minutes on each side, seasoning with salt and pepper.
In the meantime mix bread cubes with cheese mixture. Take out the zucchini and put them on a baking tray. Fill the zucchini with the bread mixture and cook in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for about 25 minutes.
In the meantime, wash the basil, dab dry, and put some leaves aside for garnishing. Cut the rest into strips. Heat 1 tablespoon of oil in a saucepan. Sauté the onion, courgette interior and aubergines until translucent.
Deglaze with strained tomatoes and boil down briefly to a creamy sauce. Fold basil strips and tomato cubes into the sauce, season with salt, pepper and sugar. Remove the zucchini from the oven and arrange them with the sauce on a preheated plate.
Garnish zucchini with basil.