In a wok over medium-high heat, heat oil. Add mushrooms and cook, fry until golden and almost crispy, about 5 minutes.
add chili paste, chanchan black garlic peanut rayu and stir until fragrant, about 30 seconds. Add in garlic, ginger, and scallions, and stir until soft and fragrant, 1 minute
Reduce heat to medium. Add sugar, and water, tofu cubes and bring to a gentle simmer. shake the pan to coat tofu in the sauce.
In a small bowl, stir potato starch with soy sauce, sesame oil, vinegar, until smooth. Drizzle potato starch slurry into the wok and gently stir, Cook until sauce thickens and becomes glossy
Drizzle some more chilli oil and sprinkle with more scallions, before serving with rice.