From seriouseats.com. Ready in 20 minutes.

Combine 1 1/2 cups water, soy sauce, sugar, and chili bean sauce in a small bowl and stir. Combine 1/4 cup water and the cornstarch in a separate bowl.

Heat the oil over a medium-high heat in a large fry pan or Dutch oven until shimmering. Add the garlic and eggplant and sprinkle with the salt. Cook, stirring occasionally, until lightly softened and fragrant, about 2 minutes.

Stir in the water, soy sauce, sugar and chili bean sauce mixture. Bring to a boil. Reduce heat to a gentle but consistent simmer and cook, uncovered, stirring or flipping eggplant occasionally, for until eggplant slices are tender and liquid has reduced by about half, about 15 minutes.

Stir the cornstarch and water mixture in its bowl to loosen it up. Stir it into the pan with the eggplant and allow it to thicken. Taste for seasoning, adding any extra salt, soy sauce, chili sauce, or sugar as desired. Remove from heat and stir in the whole basil leaves. Serve immediately.