Set oven at 400ºF degrees. Run olive oil over the skin of the eggplant, then cut it into quarters lengthwise. Place in a large cast-iron skillet. Place in preheated oven and roast for 30 minutes.
In a bowl, combine cubed bread, egg, onion, garlic, cinnamon, cumin, chili flakes and milk. Mix until evenly incorporated. Let sit for 10 minutes. Fold in ground meat. Season to taste with salt and pepper. Roll meat into tablespoon-sized balls.
Remove eggplant from oven, then place meatballs on top of roasted eggplant. Place skillet back in the oven. Roast until meatballs are cooked through, about 20 minutes.
To serve, place roasted eggplant and meatballs on a pita, then drizzle with tahini. Top with sliced scallions and garnish with lemon wedges.