Toast the bread and place flat in 1-2 casseroles. Wash and clean the zucchini, cut in half crosswise and cut lengthwise into thin slices. Melt butter in a wide saucepan, add zucchini slices and deglaze with about 5 tablespoons of water.
Cover and steam for 1-2 minutes. Season the zucchini slices with salt and pepper, remove from the stock and spread on the toast slices. Peel and finely chop the onion. Clean and clean the mushrooms and cut into thicker slices.
Heat 2 tablespoons of oil in a frying pan and add the diced onion. Sauté the onions for 1 minute, then add half the mushrooms. Fry the mushrooms over a high heat for about 5 minutes, then remove from the pan.
Heat 1 tablespoon of oil in a frying pan, sauté the remaining mushrooms and add to the other mushrooms. Heat 1 tablespoon of oil in a large frying pan and fry 4 slices of sliced pork on both sides for 3-4 minutes and place each on a slice of toast.
Fry the remaining slices in the same way. Spread the mushrooms on the slices of pork. Pour stock and cream into a pot and bring to the boil. Bind with sauce thickener. Season to taste with salt, pepper and basil. Pour sauce into the moulds and over the toast slices and sprinkle with cheese.
Bake under the grill until golden brown and garnish with basil leaves. Serve with salad.