Halve the eggplants lengthwise, hollow out the halves, salt and let them drain their bitterness.
Meanwhile, heat a few tablespoons of olive oil in a pan and fry the crushed onion, and finely chopped eggplant interior.
Once soft, add the tomato paste and spices. Stir briefly and remove from the heat.
Add the soaked in water and drained bread to the stuffing, stir well and add the tuna fillets.
Stuff the eggplants. Arrange them in a greased baking dish and put it to bake in moderately heated oven.
Finally, if desired, sprinkle the top with a little cheese. Instead of tuna from a can, you can use the same amount of fresh fish.