Slice the zucchini into thick half-moons and the onion into thin slices. Ensure the zucchini is not too thin to maintain texture while stir-frying.

Mix the seasoning ingredients: chopped green onion, minced garlic, shrimp sauce, sesame oil, and black pepper in a bowl.

Heat cooking oil in a pan and stir-fry the zucchini and onion until the onion becomes translucent and the zucchini turns golden.

Add the prepared seasoning mixture to the pan and stir-fry until the ingredients are well combined.

Add the sliced red chili and stir-fry briefly to finish. Sprinkle additional black pepper if desired.