Heat the ghee in a large pot over medium-high heat and stir in the lamb meat. Cook and stir until evenly browned. Season with allspice, cinnamon, cloves, nutmeg, and cardamom and mix well. Place a layer of onion on top of the lamb in the pot, but do not stir. Top with layers of potato, eggplant, zucchini, and tomatoes. Repeat the layers of vegetables until you have used them up, ending with tomatoes on top. Place the chile pepper in the center of the tomatoes. Season with salt. Dilute the tomato paste in the water, and pour it over the vegetables. Bring to a boil, reduce heat to low, and simmer 1 hour, until vegetables are tender. With a mortar and pestle, crush together the garlic, a pinch of salt, and the dried mint. Mix with 2 tablespoons of liquid from the pot, and drop by spoonfuls over the vegetables in the pot, but do not stir. Simmer for 5 minutes more. Transfer the stew to a wide bowl or serving dish by gently tipping the pot and letting it slide out into the serving dish, while maintaining its layers. Sprinkle with ghee, if desired.