Cook rice according to package directions, adding 1 tablespoon soy sauce, 1 teaspoon vinegar and fluff with a fork. Cover and keep warm.

Meanwhile, carefully grate tofu on large holes of a box grater. Transfer to a towel-lined plate and gently press with another towel.

Heat 2 tablespoons oil in a large nonstick skillet over medium-high. Add tofu; cook, stirring often, until turning crispy and golden brown, about 6 minutes. Add mushrooms; cook, stirring often, until softened, 3 to 4 minutes. Stir in white and light green scallion slices and garlic; cook, stirring often, until tender, about 3 minutes.

Stir in hoisin, sriracha, remaining 2 tablespoons soy sauce, and remaining 1 tablespoon oil. Cook, stirring constantly, until tofu is evenly coated and sauce is caramelized, about 2 minutes. Stir in remaining 2 teaspoons vinegar.

Leave tofu mixture and rice in lettuce leaves. Top with dark green scallion slices.