Drain and press your block of tofu for at least 20 minutes. If you don’t own a tofu press, wrap the tofu in a kitchen towel and place a large pot or pan on top of the tofu as a press. After the tofu is pressed cut into cubes.
While the tofu is pressed, prepare the sauce. In a medium bowl, whisk the soy sauce, brown sugar, hoisin, rice wine, vinegar, sesame oil, white pepper, garlic, ginger, 2 tsp cornstarch, and ⅓ cup water until combined.
After the tofu has been pressed, unwrap it and cut into ¾-inch cubes. Transfer tofu to a medium bowl, season with salt, coat in ¼ cup cornstarch, and set aside.
Place a large cast-iron skillet or just a large skillet over medium-high heat, and add the neutral oil, it should be enough to coat the bottom of the pan. When it starts shimmering, add the tofu. Cook until one side is golden brown and crisp, about 3 minutes, then flip. Cook until the other side is crisp and golden brown, another 3 minutes. Remove from the pan and transfer to a plate.
Add the red bell pepper, celery, and scallions to the pan. Cook, stirring occasionally, until the red bell pepper starts to soften while maintaining some bite and the vegetable char, about 4 minutes. Add the Sichuan peppercorns or red pepper flakes and chiles and cook until fragrant, about 1 minute. Add the tofu and sauce, and stir to coat; make sure the sauce simmers and thickens, it will take about 2 minutes.
Add the peanuts and cilantro, stir again, then serve immediately with rice.
Store leftovers in an airtight container in the fridge for up to 3 days.