Trim the ends off the courgettes and peel the aubergines, then cut both lengthwise into slices about 5mm (1/4 in) thick. Arrange the slices on a well-oiled sheet of foil and brush liberally with olive oil, then roast under a hot grill (broiler) until golden brown. Turn over and repeat on the other side.
Meanwhile, heat 3 tablespoons olive oil in a large frying pan and add the onions. Cook over a moderate heat until they start to turn golden, stirring from time to time so they cook evenly. Add the tomatoes and continue to cook for 7–8 minutes or until the sauce is thickened.
In a well-oiled shallow baking dish, arrange the courgettes, aubergines and onion and tomato sauce in layers, sprinkling each layer with grated cheese and torn basil leaves and seasoning with salt and pepper. Mix the breadcrumbs with the remaining cheese and sprinkle over the top. Drizzle over 2 tablespoons olive oil, then bake in a preheated 180ºC/350ºF/gas 4 oven for 45 minutes or until golden. Serve hot.
Excerpted with permission from Hazana: Jewish Vegetarian Cooking by Paola Gavin, published by Quadrille October 2017.