Heat up a wok until a bead of water evaporates immediately. Add 2 teaspoons of oil to the wok and sear the ground pork until done. Remove from the pan.
Make your slurry by combining the water and cornstarch in a small bowl. In the wok, add the la dou ban jiang, and swirl it with a wooden spoon or spatula until fragrant but not burnt. Add minced garlic, ginger, and the chopped whites of the green onions. Continue to stir-fry for 30 seconds.
Gently incorporate the tofu into the sauce. Add the ground pork back in, followed by the chicken stock. Bring to a boil and then simmer on low for 5 minutes.
Mix the cornstarch and water slurry into the wok. Gently stir-fry to incorporate it in. Simmer for another minute.