Quarter the prunes and finely grate the ginger. Heat the butter in a small saucepan on a low setting and roast the spices in it. Add the grated ginger and honey, toast briefly, then add the vegetable stock and quartered prunes and simmer on a low heat. Cut eggplant, bell pepper and yellow zucchini (you can use the peeled one that is left over from the starter) into medium-sized cubes. Dice the onions, finely chop or press the garlic. Heat olive oil in a large saucepan or pan, briefly roast the onions and garlic in it, then add the aubergine, bell pepper and courgette cubes, fry well. Add the chunky tomatoes and the plum-spice mixture, season with salt and pepper and simmer for at least 15 minutes. Preheat the oven to 200 degrees circulating air. During this time, cut off the upper third of the round zucchini and hollow out the remaining lower part, leaving a layer about 1 cm thick. Lightly salt the hollowed out zucchini, place on a rack in the preheated oven and cook for 20 minutes. Then fill the hollowed out zucchini up to the top with the hot ratatouille vegetables and serve immediately.