While the pork continues to roast, add 2 teaspoons of oil to the pan used to brown the eggplant. Heat on medium until hot. Add the ginger and white bottoms of the scallions; season with salt and pepper. Cook, stirring frequently, 2 to 3 minutes, or until softened and fragrant. Add the corn, soy glaze, vinegar, demi-glace and 2 cups of water; season with salt and pepper. Bring to a simmer and cook, stirring occasionally, 4 to 6 minutes, or until thoroughly combined. Remove from heat. Season with salt and pepper to taste.