Sauce: In a small saucepan combine 2 Tbsp soy sauce, 1 Tbsp fresh grated ginger, 1 Tbsp chili garlic sauce, 1 Tbsp toasted sesame oil, and 1 tsp rice vinegar. Heat over medium until warm and combined, about 5 mintues.
Prep: Meanwhile, open and drain tofu container, then flip it onto a serving plate. Chop the cucumber and onion.
Assemble: Spoon cucumber and onion over the tofu, then drizzle with warm soy sauce mixture. Serve immediately.