Remove the peel from the potatoes, cut them into small pieces and cook for about fifteen minutes.
In the meantime, cut the zucchini diagonally, remove the flesh with a small spoon, add the hollowed flesh to the potatoes form and continue for ten min. Drain the cooking water, steam the mixture a little more. Then press the potatoes and zucchini through a masher and stir the cheese into the hot mash on the spot. Add butter and egg yolks, mix well and season with salt, pepper and a pinch of nutmeg.
Cook the hollowed zucchini in lightly salted water for five minutes, remove from the water with a skimmer and drain.
Squirt or possibly fill the puree into the zucchini, sprinkle with sesame seeds and place in an ovenproof dish. Pour a little water on the bottom and bake at 200 degrees for about twenty-five minutes.
In the meantime, peel and finely chop the onions and sauté in the butter until translucent. Rinse and clean the mushrooms, cut into slices and add to the onions. Sauté for a few minutes, then add the tomato puree and the clear soup and let it boil well. Season the sauce with salt and freshly ground pepper and sprinkle with chopped basil. Serve with the stuffed zucchini.
Tip: Zucchini are a type of squash and therefore low in calories, rich in vitamins and easy to digest – just the thing for a light meal!