Begin by gathering all ingredients to streamline your cooking process. Slice your zucchini into thin, even ribbons and chop the onion.

Heat a large wok or frying pan over medium-high heat and add a splash of vegetable oil. Toss in the chopped onions, stirring frequently for about 5 minutes until they turn golden brown.

Quickly add the sliced zucchini to the wok, stirring everything together. Cook over high heat for 2-3 minutes until the zucchini is tender-crisp.

Drizzle in your soy sauce (and optional teriyaki sauce if using) while stirring continuously. Cook for another 1-2 minutes.

Remove from heat and sprinkle toasted sesame seeds over the top. Serve immediately as a fantastic side or a light main.