1. Cut the green onions, tomatoes, and potatoes and set aside.
2. Heat oil, add onions and pop the bananas, stir-fry tomatoes and potatoes evenly.
3. Add a spoonful of light soy sauce, a spoonful of dark soy sauce, a spoonful of oyster sauce, and a spoonful of ketchup. Evenly add half a bowl of water to boil to collect the juice.
4. Sprinkle chopped green onion out of the pot and eat it with rice.
If you like spicy food, you can add proper amount of chili.