Cut the eggplant and onion into bite-sized pieces.
Heat cooking oil in a pan and sauté the onions first.
When the onions become translucent, add the eggplant and stir-fry.
Season with soy sauce, mirin, and minced garlic.
Place the stir-fried eggplant and onion over rice.
Finish by topping with chopped scallions or sesame seeds.