Use a wooden spoon to clear a small area in the wok. Add the last 2 tablespoons of oil, and add the garlic, red chile peppers, ginger, and green onion. Stir until fragrant, then toss the aromatics with eggplant, and stir fry for 1 minute. Add the soy sauce, black vinegar, and sugar. Stir for 1 minute until coated and sugar is dissolved.