Prepare the pork marinade by mixing tapioca starch and soy sauce.

Marinate ground pork for 20 minutes.

Cut the tofu into 1/2-inch cubes.

Blanch the tofu in boiling water for 2-3 minutes. Drain well.

Chop the leek or green onions.

Heat oil in a wok.

Stir-fry the marinated pork until browned.

Add salt and stir.

Add the fermented black beans and mash with a ladle.

Add the chili bean paste, chicken stock, tofu, and leek or green onions.

Reduce heat and simmer for 3-4 minutes.

Mix cornstarch, water, and soy sauce.

Add the cornstarch mixture to the wok and stir gently to thicken the sauce.

Serve hot, garnished with freshly ground Szechuan pepper.