Preheat oven to 400 degrees F. Line a baking sheet with parchment paper.
Cut eggplant in half lengthwise. Use sharp knife to score eggplant in a crisscross pattern, making sure not to cut through the skin. Drizzle olive oil on flesh. Combine garlic with za'atar, salt, and pepper and spread mixture on cut sides. Place eggplant on middle rack in the oven and roast for 1 hour or until tender.
Meanwhile, make feta yogurt sauce. Puree yogurt with feta and lemon juice until well combined. Stir in dill, lemon zest, and garlic. Season sauce with salt and pepper and set aside.
Grate tomatoes using coarse grater. Discard tomato skins. Combine grated tomatoes with 2 tablespoons extra virgin olive and season with salt and pepper.
Spread feta yogurt sauce on serving platter and place roasted eggplant on top. Spoon tomato salsa on top and sprinkle chopped parsley and walnuts. Finish with Maldon salt and an extra drizzle of extra virgin olive oil. Serve warm.