For this colourful dish from Provence, you need very fresh and tender summer vegetables and a mandolin to cut them finely so the final consistency is more that of a moist loaf than a gratin.
2 large onions
Glass of Passata
Parmesan to sprinkle after baking
Slice all three vegetables finely then nestle them in alternate order inside an oiled Terracotta dish. Season with salt and pepper, generous thyme and a line of olive oil. Pour the Passata on top and decorate with the basil.
Put in a warm oven for a minimum of 45 minutes, until the vegetables have melted into each other. Drain by tipping the dish if they have released to much water. Sprinkle with more olive oil and parmesan and serve very hot.