Rinse the oysters thoroughly and prepare them.
Cut zucchini, onion, green onion, and spicy green chili into bite-sized pieces.
Heat cooking oil in a pan and stir-fry onion and zucchini.
Add oysters, green onion, and spicy green chili.
Season with chili powder, soy sauce, minced garlic, and black pepper.
Once the oysters are lightly cooked, turn off the heat and serve.