Don't peel the aubergines: cut them in half, lengthways; make some incisions lightly on the two cut surfaces, cover this part with salt and let them stand for an hour or so.
This will bring out drops of water, which should be wiped away with the salt.
Put the onions, and the sliced tomatoes, in a fireproof dish: lay the aubergines on top of them, add a dash of pepper and seal the dish hermetically with a piece of paper, or metal foil tied on top.
Let the vegetables cook for one hour in the oven— literally in their own juices.
Add no water.
Then arrange the aubergines in a dish, garnishing each with onion, tomato, anchovies, and hard-boiled egg; and capers and olives too if you like.
Serve chilled.