As easy to cook as it is delicious to taste, this vegetable gratin will be served directly in its baking dish, preferably in glazed terracotta.
Peel the onions and chop them. Wash the aubergines, zucchini and tomatoes, wipe them and cut them into fairly thin slices. Peel the garlic cloves and mince them finely, mix them with the orange zest. Lightly oil a gratin dish and sprinkle the bottom with a few pinches of fresh thyme.
Spread the sliced onions in the bottom, lightly salt and pepper. Then add the aubergines, a little garlic, the courgettes, a little thyme, the tomatoes and the rest of the garlic.
Lightly salt and pepper. Lightly drizzle with olive oil at regular intervals. Cover the dish with aluminum foil and place it in the oven preheated to 180°C. Cook slowly for 1 hour until the vegetables are tender and serve immediately.
You can also slip in the middle of the vegetables a few anchovy fillets in oil (or salt, and then carefully desalted) cut into pieces. In this case, do not over-salt the dish.
Source:The Regional Cuisines of France. Editions du Fanal.