Prepare the tofu: Cut the 500 grams of tofu into medium cubes. Set aside while you prepare the rest of the ingredients. Try to be gentle with the tofu so it keeps its shape.
Cook the pork: Heat 2 tablespoons of oil in a pan over medium heat. Add the ground pork and cook until browned and slightly crispy. Break it apart with a spatula as it cooks.
Build the flavor: Push the pork to one side of the pan. Add the doubanjiang and fermented black beans to the oil and cook for about 30 seconds to bring out their flavor. Then add the garlic, ginger, onion, red bell pepper, and green chili. Stir everything together and cook until the aromatics are soft and fragrant.
Add the sauces and water: Pour in the soy sauce, oyster sauce, sugar, and 2 cups of water. Stir well and let it come to a gentle simmer.
Add the tofu: Carefully add the tofu cubes to the pan. Stir gently to avoid breaking them. Let the mixture simmer for about 4–5 minutes so the tofu can soak up the sauce.
Thicken the sauce: Give your cornstarch slurry a quick stir (2 tablespoons cornstarch mixed with 3 tablespoons water), then pour it into the pan. Stir gently and let it simmer for another 1–2 minutes, until the sauce thickens and becomes glossy.
Finish and serve: Drizzle in the sesame oil and season with salt to taste. Turn off the heat and top with chopped green onion. Serve hot with freshly cooked rice.