Prepare Ingredients: Wash and peel the zucchini and onion. Slice zucchini into thin ribbons and onion into half-moons. Set aside.

Heat Oil: In a large wok or skillet, pour in 2 tablespoons of oil and heat over high heat until shimmering.

Cook Onions: Add the sliced onions and stir-fry for 2-3 minutes until soft and caramelized.

Add Zucchini: Stir in the zucchini ribbons and cook for 5-7 minutes, stirring continuously, until tender-crisp.

Stir in Soy Sauce: Add 2-3 tablespoons soy sauce, mixing well to coat the vegetables. Let sizzle for 1-2 minutes.

Finish and Garnish: Remove from heat and sprinkle with toasted sesame seeds before serving hot.