Heat the oven to medium high heat. Oil a medium size dish (the dish should have a lid).
To make the tahini, put the paste in a food processor, add garlic, parsley, salt and pepper. Gradually add lemon juice and a cup of cold water. The result should be a runny mixture, that you'd be able to pour easily.
Thinly slice all the vegetables. Put half of the tomatoes on the bottom of the dish. Put the Fish on top of the tomatoes and season it well. Cover the fish with the rest of the tomatoes. Add the chili pepper slices, top with onion rings and after that with eggplant slices.
Pour the tahini evenly on top of the eggplant.
Cover the dish and bake in an oven for half an hour. After this, drizzle the eggplants with olive oil and bake uncovered until golden.
Serve hot with fresh lemon on the side.