For the vegetable lasagna, first stir soup and whipped cream for the bechamel sauce. Melt butter in a saucepan, add flour and sweat. Whisk in top mixture in a thin stream. Cook 2 minutes over medium heat, stirring throughout. Stir in tomatoes. Simmer over medium heat for 5 minutes, stirring constantly. Season with salt, pepper and nutmeg.
Rinse and finely dice zucchini. Halve peppers, remove seeds and finely dice flesh. Peel garlic and chop finely. Heat oil in a saucepan. Sauté garlic and vegetables in it. Pluck basil and chop finely. Season vegetables with salt, pepper and basil. Let mozzarella drain well and cut into thin slices.
Layer mozzarella, vegetables, lasagna sheets and bechamel sauce alternately in a mold. Finally, top with mozzarella.
Bake in a hot oven at 200 degrees (gas 3, convection oven not recommended) on the 2nd rack from the bottom for 40 minutes. Cover vegetable lasagna only after 20 minutes. Let rest for 10 minutes before serving.