Begin by draining the firm or extra-firm tofu, then wrap it in a clean towel to press out the excess moisture for at least 15 minutes. Cut the tofu into 1-inch cubes and marinate in a bowl with soy sauce and sesame oil for about 10 minutes.

In a separate small bowl, mix together the remaining soy sauce, minced garlic, freshly grated ginger, and optional red pepper flakes. Set aside for later use.

Heat a non-stick skillet over medium-high heat and add a tablespoon of sesame oil. Once the oil is shimmering, carefully add the marinated tofu cubes and sauté for 5-7 minutes until golden brown and crispy. Remove from the pan and set aside.

In the same skillet, add more oil if necessary, then toss in minced garlic and ginger. Sauté for about 30 seconds until fragrant, then quickly add the sliced cabbage and carrots. Stir-fry them over high heat for 3-5 minutes until the cabbage wilts and the carrots are tender-crisp.

Return the crispy tofu to the skillet. Pour the prepared stir-fry sauce over and toss everything together. Cook for an additional minute to allow flavors to meld.

Remove from heat and transfer to a serving dish. Sprinkle sesame seeds on top and serve immediately, optionally over warm rice or noodles.