Cut the onion into cubes. Core the tomatoes and dice the pulp. Cut the zucchini into slices approx. 3 mm thick. Slice olives. Sweat the onion cubes in the olive oil, squeeze the garlic clove and sweat briefly. Add diced tomatoes and sauté briefly. Deglaze with the vegetable stock. Add zucchini, olive slices, rosemary and thyme sprigs and season with salt and pepper. Simmer for approx. 5 minutes. Remove sprigs of rosemary and thyme. Just before serving, add the basil cut into strips. If necessary, season again with salt and pepper.