Combine all the tofu marinade ingredients in a bowl and stir until the sugar has melted.
To prepare the tofu, coat the slices generously with 1 tablespoon of cornstarch. Then, pour the marinade over and coat the tofu slices evenly with it.
Next, heat a non-stick skillet and add 2 teaspoons of oil. Pan-fry the tofu slices until golden brown. Transfer to a plate and set it aside.
Now, heat a large wok and add 2 teaspoons of oil. Add the gai lan and quickly toss until the leaves are covered with oil. Season with ½ teaspoon of salt and sugar. Transfer to a bowl for later.
Meanwhile, mix together 1 teaspoon of cornstarch and ½ teaspoon of salt in ⅓ cup of water until well-combined.
Using the same wok, add another tablespoon of oil and sauté the ginger slices until aromatic.
Continue to cook the garlic slices and chile for a few seconds. Place the gai lan back in and add a swirl of Shaoxing wine, then toss to combine.
Next, fold in the tofu and add in the cornstarch slurry. Toss all the ingredients until all incorporated or until most of the sauce has been absorbed.
Turn off the heat and serve this dish warm with a side of rice.