Prepare the tofu and eggplants: Press the tofu for at least 10 minutes to drain any excess liquid. Place the tofu in a bowl. Crumble the tofu with your hands or a fork then set aside.
While the tofu is being pressed, puncture each eggplant four or five times around its body, using a fork. Place the eggplants in a microwave-safe dish and cover with a microwave-safe lid. Microwave for 2 minutes on high, or until the eggplants are wrinkly on the outside and tender to the touch. Flip the eggplants over and microwave, covered, for another 2 minutes on high. Let cool for 5 minutes. Alternatively, you can boil your eggplants in a pot of water until tender, about 6 minutes.
Prepare the sauce: In a medium-sized bowl, mix together all the sauce ingredients and adjust to your taste, then set side.
Prepare the filling: Heat a large skillet or wok over medium-high heat. Add the oil. Sauté the onion, ginger and Szechuan pepper (if using) until aromatic, about 2 minutes. Add the crumbled tofu, carrot, bell pepper, mushrooms and scallions. Sauté until the bell pepper and mushrooms are cooked through and the tofu is slightly golden brown, about 4 minutes. Continue to cook, turning to lightly crisp it, for another 2 minutes. The tofu will start to resemble minced meat as the water from the tofu evaporates.
Give the sauce a good mix again. Lower the heat to medium and pour the sauce into the pan. Stir well until the sauce thickens, 2 minutes. Taste the tofu and adjust the seasoning as needed. Turn off the heat and set the pan aside.
Slice through the middle of each eggplant lengthwise and carefully open them. Scoop a generous amount of the filling into each eggplant. Garnish with chopped scallion and sliced chile, if desired. Enjoy with rice or as is.