Toss tofu cubes in cornstarch and salt, then pan-fry until crisp; set aside.
Heat vegetable oil in a wok, sauté dry red chilies, ginger, and garlic paste.
Whisk together soy sauce, vinegar, sugar, and water.
Toss crispy tofu and roasted peanuts into the wok, pour in sauce mixture, and cook until glazed.