RINSE THE RICE, cover it with water and set it aside to soak while you prepare the rest of the vegetables. Preheat the oven to 375F. Warm the oil and butter in a large skillet. Add the eggplant and onion, salt them lightly, and rapidly saute them to distribute the oil. Cook over medium heat until the eggplant is soft but not mushy, about 5 minutes. Add the peppers, tomatoes, spices (including the pepper), parsley and more salt to taste. Stir carefully, combining everything well. Drain the rice and add it to the pan along with 3 cups water. Turn up the heat to bring the water to a boil, then transfer everything to a baking dish, such as a large, earthenware gratin dish. Lay a piece of parchment over the top, cover with foil, and bake until the rice is done, about 45 minutes. Toss the diced cheese, if you're using it, into the rice and serve. Serves 4 as a main course or 6 to 8 as a side dish.