Mix Chinkiang vinegar, light soy sauce, Shaoxing wine, spicy fermented bean paste, and sugar in a small bowl.

Heat peanut oil in a small saucepan over medium heat until warm. Add ginger and garlic. Stir and cook until fragrant. Turn to medium low heat. Add the vinegar mixture. Stir and cook until bringing to a simmer. While grilling eggplant, put the saucepan on the grill, over indirect heat to keep warm. Add a bit of water if the sauce gets too thick.

Halve the eggplants lengthwise. Score the inside flesh in a criss-cross pattern using the tip of a small knife. Cut as close to the skin as you can without cutting through it.

Light one chimney full of charcoal. When all the charcoal is lit and covered with gray ash, put on heat resistant gloves, pour the charcoal into the grill, and spread it in an even layer. Set the cooking grate in place, cover the grill, and preheat for 5 minutes. If using a gas grill, set all the burners to high heat and preheat for 15 minutes. Clean the cooking grate. Make sure the grill has reached medium-high heat (*see footnote 1).

While waiting for the grill to heat, brush cut sides of the eggplant slices with peanut oil. Season with salt.

Grill eggplant over medium-high heat with the lid open, for 8 to 10 minutes, until the surfaces are charred with dark grill marks. Flip once in the middle. If the eggplant gets charred too quickly, move to the cooler side of the grill, but not too far from the fire. Cook until the texture becomes creamy. Transfer to a plate to cool.

Pour sauce onto eggplant right before serving. Serve warm, or at room temperature.