Wash the zucchini and onions. Slice the zucchini into thin ribbons or half-moons; cut the onion into thin wedges.

Preheat a large wok or stir-fry pan over high heat for about 2 minutes.

Add a tablespoon of oil to the hot wok and toss in the sliced onions. Stir continuously for 2-3 minutes until translucent and caramelized.

Quickly add zucchini ribbons, stirring vigorously for 3-5 minutes until vibrant green but retain slight crunch.

Pour in the soy sauce, mix well and cook for another 1-2 minutes ensuring every piece is coated.

Remove from heat and transfer to a serving dish. Sprinkle with toasted sesame seeds before serving.