If using American eggplant, desalt if desired by placing in a colander and sprinkling with salt, and letting sit for 30 minutes
Marinate the ground pork in the soy sauce, pepper and cornstarch for 15 minutes
Cut the eggplant into pieces approximately 1 inch long and 1/2-inch thick (do not peel)
Finely chop the garlic and ginger
Cut the green onion on the diagonal into 1-inch pieces
Heat the wok over medium-high to high heat
Add 2 tablespoons oil
When the oil is hot, add the eggplant
Stir-fry the eggplant until softened (about 5 minutes)
Remove from the wok
Add 2 tablespoons oil to the wok
When the oil is hot, add the bean sauce
Cook for 1 minute, then add the garlic and ginger
Stir-fry until aromatic
Add the ground pork
Stir fry until the pork changes color and is nearly cooked through
Add the eggplant back into the pan
Sprinkle the black rice vinegar and soy sauce over
Stir in the sugar and the green onion
Mix thoroughly and serve