Mince the onion.

Heat half of the salad oil in a pan over medium heat, add the onion, and sauté for about 5 minutes until softened. Remove and let cool.

In a bowl, mix the ground meat with salt, pepper, and nutmeg until sticky. Add the cooled onion and egg, then mix thoroughly. Shape into two patties, ensuring to remove air pockets.

Heat the remaining salad oil in the pan over medium-high heat. Place the patties in the pan, indent the center slightly, and cook for 3 minutes until browned. Flip, add 50ml water, cover, and steam over medium-low heat for 7–10 minutes.

Push the patties to the side, remove excess oil with a paper towel, and add the sauce ingredients. Simmer for 3 minutes, coating the patties with the sauce.