Prick the sweet potatoes several times with a fork, then place them on a baking sheet. Transfer the potatoes to the oven and roast for 50-60 minutes, until they are extremely tender.
Meanwhile, heat the ghee in a large skillet over medium heat. Add the onion and sauté until translucent, about 6-7 minutes. Add the garlic and cook until fragrant, about 30 seconds.
Add the ground turkey to the skillet, breaking it up with a spoon. Season with cumin, cinnamon, coriander, turmeric, salt, and pepper. Cook the turkey until it has browned and is no longer pink, about 8-9 minutes. Remove the skillet from the heat and cover to keep warm.
Whisk the tahini, lemon juice, garlic, and salt together in a small mixing bowl. Gradually whisk in the warm water, adding more, if necessary, until a smooth consistency is reached.
Remove the sweet potatoes from the oven, then carefully slit them in half vertically and spread them open. Divide the turkey mixture between the sweet potatoes, then top with the tahini dressing, fresh parsley, and sesame seeds.