On a work surface, cut the eggplants in half lengthwise. Using a small knife, make incisions in the flesh of the eggplants, without piercing the skin. Brush the eggplants with 30 ml (2 tablespoons) of the oil. Season with salt and pepper. Place the eggplant flesh side down on the grill with the tomato and garlic. Cook for 5 minutes and remove the eggplants. Set aside on a plate. Continue cooking for 5 minutes on all sides or until tomato and garlic are cooked and well roasted. Set aside with the eggplants and let cool. Keep the barbecue lit.
On a work surface, remove the skin from the tomato and the skin from the roasted garlic cloves. Compost them. Chop the tomato and garlic, then place in a bowl. Using a spoon, remove the flesh from the eggplants, keeping the skin and a thin layer of flesh inside to keep their shape. Coarsely chop the flesh and add it to the bowl with the garlic and tomato.
Add the chickpeas. Using a fork, mash all ingredients coarsely. Add the remaining oil, harissa and spices. Season with salt and pepper and mix well.
Place the eggplants in a cast iron pan, skin side down. Fill the cavities with the chickpea mixture.
Place the pan on the barbecue grill. Close the lid and cook for 5 minutes.
Tahini sauce
Meanwhile, in a small bowl, mix the tahini and water. Season with salt and pepper. Stir in yogurt.
Remove the pan from the barbecue. Drizzle with tahini sauce and pomegranate seeds. Sprinkle with mint and lemon zest.
