Prepare and fry the tofu: Press the tofu with a heavy object to remove excess moisture, drain the tofu, and cut the pressed tofu into bite-sized pieces or cubes. Heat cooking oil in a large skillet or non-stick pan over medium-high heat. Fry the tofu cubes in a single layer until golden and crispy on all sides. Remove the tofu from the pan and set aside.
Prepare the eggplant: Sprinkle salt over the eggplant pieces to remove bitterness, and drain the liquid out after 10 minutes. Rinse and pat dry. Coat the drained eggplant pieces with cornstarch and set aside. Do not forget to dice the red bell pepper, too.
Prepare the sauce: In a large bowl, whisk together soy sauce, coconut sugar, Dou ban jiang vegetable broth, and Zhejiang black vinegar.
Cook the eggplant: Use the remaining oil in the same skillet, add minced garlic and ginger, and stir-fry until fragrant. Add the coated eggplant pieces and cook until golden brown and tender.
Combine and add sauce: Return the diced tofu and red bell pepper to the pan with the eggplants, continuing to stir fry for 20 seconds. Pour the premade sauce over the mixture and toss to coat evenly. Let it simmer for a few minutes until the sauce thickens slightly.
Serve: Serve the eggplant and tofu stir-fry hot cooked white rice. Garnish with sliced green onion curls and sesame seeds for extra flavor and texture.