01 - Whisk together soy sauce, mirin, sesame oil, and sugar in a small bowl until sugar dissolves completely.
02 - Heat neutral oil in a large skillet or wok over medium-high heat until shimmering.
03 - Add sliced onions to the hot pan. Stir fry for 2 minutes until edges begin to soften and turn translucent.
04 - Add minced garlic and ginger. Cook for 30 seconds, stirring constantly until fragrant but not browned.
05 - Add zucchini slices to the pan. Stir fry for 3–4 minutes until just tender but still retaining slight crunch.
06 - Pour prepared sauce over vegetables. Toss to coat evenly and cook for 1–2 minutes until sauce thickens slightly and vegetables appear glossy.
07 - Remove from heat immediately. Sprinkle with green onions and toasted sesame seeds. Serve hot as a side dish or over steamed rice.