Cut 2 eggplants in half length-wise and with a spoon scoop out the flesh to make shell-like shapes. Set the scooped flesh aside. Season eggplant shells with salt, drizzle with olive oil, place on a baking tray lined with baking paper and put in preheated oven to bake at 200°C / 392°F for about 30 minutes.
Prepare your lemon tahini sauce: in a bowl (or food processor) place tahini, minced garlic, juice of 1/2 lemon, salt and pepper to taste and a bit of water. Mix well, and add more water as needed, depending how thick you want your sauce.
Prepare couscous as per package instructions. Place 1 cup of couscous in a bowl and pour over 1 cup of salted boiling water. Cover with a lid and let sit for about 5 minutes, or until the couscous has soaked up the liquid. Run through with a fork to loosen it and set aside.
Take leftover scooped eggplant flesh and chop into smaller chunks. Peel and finely chop onion and garlic cloves. Wash and dry cherry tomatoes and zucchini. Cut cherry tomatoes in half and grate zucchini.
Heat a pan on medium and add a table spoon of olive oil. Add onion and garlic and stir-fry for a couple of minutes, until the onion turns translucent. Add chopped eggplant flesh, cherry tomatoes and grated zucchini. Season with salt and pepper and cook until soft. Add couscous and drizzle with lemon juice, combine well and remove from stove.
When the eggplant shells are baked and soft to the touch, remove from oven and fill with the couscous and vegetable mixture. Set on plates, drizzle with tahini sauce and sprinkle with finely chopped parsley. Top with a drizzle of olive oil and serve.