Preheat oven to 400 F degrees.
To make the spice mixture, in a small bowl, mix together the cumin, coriander, chili, paprika, preserved lemon paste, olive oil, and ½ teaspoon of salt. Set aside 2 tablespoons of the spice mixture.
Cut the eggplants in half lengthwise. Score the flesh of each half with deep, diagonal crisscross cuts, making sure not to pierce the skin. Brush the spice mixture over each half, spreading it evenly and place the eggplant halves on a baking sheet, cut side up. Put in the oven and roast until the flesh is completely soft, 40-50 minutes.
While the eggplant bakes, bring water to boil. Stir in bulgur and let simmer for 12 minutes. Drain off any excess water and fluff with a fork.
Soak the barberries in warm water for 10 minutes, drain and set aside.
To make tahini yogurt drizzle, whisk together yogurt, garlic clove, tahini, fresh lemon juice, ground cumin, and kosher salt in a small bowl, adding ice water as needed to thin it out until you reach your desired consistency.
Very gently scoop the eggplant flesh from the eggplants, being sure to leave about ¼-inch of flesh in the skins. Roughly chop the eggplant flesh.
Heat the remaining spice mixture over medium heat and add the cooked bulgur, then fold in the chopped eggplant flesh, drained barberries, pine nuts, green onions, and fresh herbs. Off heat, add a splash of red wine vinegar, preserved lemon paste, crushed red pepper flakes and adjust salt and pepper to taste.
Stuff the eggplant with the bulgur mixture. It’s okay if some of it falls alongside the eggplant. Return the eggplants to the oven and cook for 20 minutes.
Transfer eggplants to a serving platter and top with parsley, green onions, lots of tahini yogurt dressing and pomegranate seeds (optional).