Cut the sweet potato into cubes.
Finely chop the onion and carrot.
Heat cooking oil in a pan over medium-low heat.
Add sweet potato, onion, and carrot, and stir-fry for 5 minutes.
Season with salt and pepper.
Top with mozzarella cheese, cover with a lid, and cook for 2 minutes until the cheese melts.
Transfer the finished Jinjonku to a plate.