1-Wash and slice the zucchinis into thin: Wash and slice the zucchinis into thin ribbons or strips.
2-Peel and thinly slice the onion: Peel and thinly slice the onion.
3-Preheat a wok or skillet over high: Preheat a wok or skillet over high heat for about 2 minutes.
4-Add a splash of oil and swirl: Add a splash of oil and swirl it around to coat the surface.
5-Toss the sliced onions into the hot: Toss the sliced onions into the hot pan and sauté for 2-3 minutes.
6-Add the zucchini ribbons and stir-fry for: Add the zucchini ribbons and stir-fry for 2-3 minutes.
7-Pour soy sauce over the vegetables and: Pour soy sauce over the vegetables and stir quickly to coat.
8-Remove the pan from heat and transfer: Remove the pan from heat and transfer stir-fry to a serving dish.
9-Sprinkle toasted sesame seeds on top before: Sprinkle toasted sesame seeds on top before serving.