In a small bowl, whisk together soy sauce, sugar, rice vinegar ; set aside.
Roughly chop the block of tofu into small, irregular shapes.
Heat vegetable oil in a skillet over medium heat. Add tofu and sear until golden brown, about 2-3 minutes on each side. then stir and let cook until golden brown on bottom again. Repeat this process until most of the tofu is golden and crispy on the edges (about 10 minutes total).
Stir in the garlic, ginger, red pepper flakes, and half of the green onions and cook until fragrant, about 30 seconds more.
Stir in soy sauce mixture and stir to coat, cook until sauce has reduced slightly, about 2-3 minutes.
Spoon tofu onto lettuce wrap, sprinkle with green onions.
Notes
Top with remaining green onions or additional you like. Enjoy immediately.