Bring a medium pot of water to a boil. Add the tofu slices and blanch them for 30 seconds. Drain and set aside.
Heat 1 tablespoon of oil in your wok over high heat. Stir-fry the soybean sprouts for about 2-3 minutes. Add the enoki mushrooms, spreading the mushrooms out in a single layer, and leaving them for about 20 seconds. Then stir-fry until the mushrooms have wilted, 1 minute. Turn off the heat, pick a large heatproof serving bowl with some depth, and spread the bean sprouts and enoki mushrooms around the bottom of the bowl.
Add another tablespoon of oil to the wok over medium-low heat, along with the ginger slice and Sichuan peppercorns. Cook for 3 minutes, until fragrant, then remove the peppercorns and ginger, leaving the oil behind in the wok.
To the oil, add the white parts of the scallions, the spicy bean paste, and tomato paste. Fry for 1 minute, until the oil is red, then stir in the blanched tofu. Stir-fry for 30 seconds.
Then add the water, sugar, and light soy sauce. Bring to a simmer. Then add the cornstarch slurry. When it’s thickened, add this mixture on top of the mushrooms and bean sprouts.
Top with the minced garlic, chili flakes, and Sichuan peppercorn powder on top. In a small saucepan, heat the remaining 2 tablespoons of oil until it shimmers. Pour hot oil into the garlic, chili, and peppercorn powder; the ingredients should sizzle immediately. Then sprinkle over the green parts of the scallions and the cilantro. Serve immediately.